Hi guys! It’s been years now since I first made my simple Rainbow Cake here on Kerry Cooks, and in that time, Rainbow Cake’s have become even more crazily popular! BBC Good Food even featured one in their magazine (although it’s apparently not nearly as reliable as mine, judging by the reviews!).
If you’re thinking of making one, rest assured that Rainbow Cake can be easy and stress free. My recipe is a simple Victoria Sponge recipe that’s been adapted for bigger quantities. Once made, the batter is divided into six and the colouring added to give the bright rainbow layers. HUNDREDS of people have made it with great success – check out the comments!
What type of food colouring should I use?
It’s really important that you use highly concentrated food colourings for this cake. These are normally called gel or paste colours. If you use an old fashioned liquid food colouring, the cake will taste horrible, and the colours will be insipid and weak (NOT a vivid rainbow!). The brands to go for are –
Yes – Sugarflair, Americolor, Wilton,
No – Dr Oetker (gel), Silver spoon (gel), any liquid colours whatsoever
As mentioned in the recipe post, I normally stick to Sugarflair for every colour except purple (Sugarflair’s grape violet is too dull in my opinion) – I use Americolor’s Electric Purple instead.
If you have a specialist baking supplies shop nearby, you should be able to find gel colours for between £2.50 and £3 per pot. Failing that, you can buy sets of gel colours specifically for Rainbow Cake’s from eBay, and other online shops too – I recently bought some Americolor’s from Fair Cake.
I wrote a whole post on the subject of colouring cake sponge here.
Is food colouring dangerous / can I overdose on it?
If you’re concerned about consuming the E numbers and artificial bits and bobs in gel food colouring, do not make a rainbow cake.
Could I add other flavourings to my Rainbow Cake?
Yes! You could add a flavouring extract such as strawberry, almond, lemon, or even something more exotic like bubblegum.
What size cake tins did you use?
I used 6 inch disposable ‘flan cases’ to bake my cakes, which I bought from Wilkinson’s (UK). 6 inch tins is why my Rainbow Cake was so very tall! Depending on how tall you’d like your cake to be, 6, 7, or 8 disposable tins would work great – you’d just get either a taller or less tall cake. If you want a cake that’s bigger than 8 inches, you’ll need to scale up the recipe.
Lots of supermarkets and pound shops sell disposable cake tins too, so stock up whenever you see them. I even re-use mine, with a quick rinse and turn in the dishwasher.
How did you prep the tin foil tins before using?
The great things about disposable tins is that cakes seem to come out of them really easily. I simply prep by brushing melted butter around the bottom and sides of the tin (alternatively, you could use a cake release product). If your cake does get stuck, never fear, simply cut the tin foil sides of the tins at about every inch, and then flatten the sides – you should then be able to get a palette knife under the cake to loosen it.
How high will my layers rise?
The layers should be between 1 and 2 cm high, depending on what size tin you use. If your cakes don’t seem to have risen, troubleshoot by checking your self-raising flour – is it well within date? You should also try to get the cakes into the oven as soon as possible once the flour is added to the batter – not easy given that you’re dividing it into six and adding the colours, but work as quickly as you can.
Can you make the layers ahead?
Yes! In fact, if you can make them one or two days before you want to serve your cake, its ideal. When a cake is freshly baked, it’s very crumbly and difficult to stack. I recommend baking your cakes, wrapping them in clingfilm and popping them into the freezer, and then unwrapping and decorating the next day. It will make decorating so much easier, trust me!
Is it okay to leave the batter to sit while I bake three cakes?
6 disposable cake tins between 6 and 8 inches should fit easily into a normal sized oven with three shelves. If all of your tins can’t fit into the oven at once, there’s no harm letting half the mixture sit as long as it’s for a fairly short time (your cakes should be cooked in around 15 minutes). Cake mixture shouldn’t sit around for too long once the flour has been added, or the cake will become tough when cooked.
Does the frosting set firm?
The cream cheese frosting I recommend will set firm to the touch, although it may need some help from the fridge on a very hot day. When you’re decorating the cake, you’ll need to apply multiple layers of frosting, setting in the fridge.
I’m having problems with my cream cheese frosting, any advice?
Cream cheese frosting can be tricky – I wrote a whole post on how to get it right. This method is so easy and it has NEVER failed for me!
Could I use another type of frosting to cream cheese frosting?
Of course! It’s your Rainbow Cake. You could also use a buttercream, or perhaps a chocolate frosting. It would be really nice to try one flavoured with strawberry or cherry extract too. If you’re not too confident with baking, you could even buy a pre-made frosting. Or you could even use jam.
Lots of Rainbow Cake recipes also recommend a Swiss Meringue Frosting, which is also white and popular due to not being overly sweet. If you’d like to give it a go, try this recipe by the reliable Annie’s Eats (you’ll want to double the quantities).
Could I use less sugar in the cream cheese frosting?
Definitely! Any frosting recipe is a guide – I normally add sugar 100g at a time until I’m happy with the sweetness and thickness.
How should I decorate my Rainbow Cake?
Excellent question! The answer is – however you want! I love a smooth, plain white finish (to which you can add rainbow coloured sprinkles if you want) which doesn’t give any hint to the cake inside, so that when it’s cut, its a magical surprise! This is also the most low-maintenance method of decorating your Rainbow Cake.
It is possible to cover your cream cheese frosting in fondant if you’d prefer too.
If you’d like to experiment with your decoration, check out my Rainbow Cake board on Pinterest for more inspiration! The rainbow ruffle and rainbow fondant heart cakes are especially awesome.
Do I need to use dowels to support my cake?
My cake didn’t have any support from dowels, and it always holds up just fine. Cream cheese frosting is very sticky and holds the cake together well. However, when you’re building your cake, I recommend sticking it to your cakeboard/serving plate with a little cream cheese frosting ‘glue’ and building it two layers at a time, popping it into the fridge for 20 minutes each time to allow the layers to set firm before adding more.
How should I transport my Rainbow Cake?
I transported mine in a large shopping bag (the big bag for life types from Marks and Spencer) and it did get a little knocked en route (on the BUS!). If your cake needs to be transported, I’d recommend a taller cake carrier (Lakeland and cake supplies shops do some lovely ones).
Do you have any other Rainbow Cake questions? Let me know what they are in the comments and I’ll do my best to help!
x Kerry
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Faheema Vallie says
February 1, 2019 at 9:37 amHi Kerry has the rainbow cake recipe already been adapted to make the 6 layers.. or should I double the ingredients myself??
Thomas Ruff says
April 26, 2018 at 7:44 pmHi Kerry, could i do a white chocoalte ganache on top or Do you think that will ruin the frosting?
Kerry Cooks says
April 28, 2018 at 11:50 amYou could definitely do a white chocolate cream cheese frosting! I’m not sure about a ganache as I’ve never made one, but in theory it should work 🙂
Elizabeth says
April 4, 2018 at 2:20 pmHi Kerry have just made your rainbow ,and froze them party a week sunday ,will they dry out? Also doing y frosting .and thinking of making maramallow fondan,does it wo ok
Kerry Cooks says
April 14, 2018 at 8:53 pmHi Elizabeth, no a cake can’t dry out in the freezer – being frozen keeps them fresh. I haven’t tried marshmallow fondant on the cake but it sounds delish!
Anna says
October 21, 2017 at 10:21 pmhi, do you think I can use some jam/fruits/berries in between the layers?
Kerry Cooks says
October 24, 2017 at 6:55 pmHey Anna, definitely! You could use anything you would put in any cake – whipped cream and fruits, or stick with the cream cheese frosting and add jam and fruit too.
Nirvana says
October 18, 2017 at 2:32 pmHi, How many days can a cake last in the freezer? for example if I make the cakes on a Monday, freeze them and decorate on a wednesday to be served on a thursday (in the office) would that work or would the SPONGE go stale?
Kerry Cooks says
October 18, 2017 at 7:00 pmHello! You can freeze cakes (well wrapped in cling/tin foil) for three months! It wouldn’t go stale at all 🙂
Geena Varghese says
September 28, 2017 at 10:24 amHai Kerry,
I want to bake this for my son’s birthday.Can I frost this with whipping cream and keep in fridge fully set to use for next day evening?Will it hold?Also I am planning to bake it in a large disposable roasting tray from wilko as i need it for around 35 people.What amount should I use please.
Kerry Cooks says
September 30, 2017 at 9:55 amHi Genna – I’ve never frosted it with whipped cream, so I don’t know how long it will take to set. In the Rainbow Cake post, there’s some guidance on scaling up your recipe – I’d advise tripling it to make sure you definitely have enough mix.
Geena Varghese says
October 13, 2017 at 11:17 pmhai Kerry
Thanks a lot for the reply….I made it and no need to say it was a huge hit..Made some cup cakes along as well to make sure it serves for all…………..I wish if I could post the pic…….
nina perera says
September 13, 2017 at 3:35 pmHi! Im planning on baking this f my daughtErs birthday party bug was thinking about a 9″ tin, how would i adjust the quantities? Thank you!
Kerry Cooks says
September 13, 2017 at 6:33 pmWith a 9 inch tin you’ll only want to increase the quantities slightly – the recipe divides nicely into 6 then times by 7 – so you’ll end up with 7 eggs, and 415g of most of the ingredients
nina perera says
September 13, 2017 at 8:10 pmThank you so much (aNd sorry about all the typos!)
Aimee says
October 5, 2017 at 3:23 amHi! I just tried a 9 inch using the quantities suggested ÷6 ×7 and I have 6 very thin sad looking cakes! ☹ do you think this was due to the size or OVERMixing…? Wanted this for my husband’s 30th but so far not looking promising!! I was following your recommended timeline so do have TIme to try again..
Kerry Cooks says
October 11, 2017 at 7:45 pmSo sorry to hear that! Try doing it x 8 or even 10, then if you have a bit more batter than you need you can just make a few rainbow cupcakes.
nina perera says
October 12, 2017 at 9:36 amHi ive been meaning to reply as i made the 9″ cake foR my daughters birthday and it worked amazingly. I have to say i started out feeling a bit worried as it just fidnt Look like enough mixture, and they do look rather thin and flat , however the magic happens when you stack them all up- it actUally ends up being a pretty substantial cake! I cheated and used betty crocker buttercream (i used 3 tubs! Half a tub between each layer then half a tub as a crumb coat Before covering with roYal iCing. It looked sTunning when it was cut open and i had so many compliments!
Jade harding says
September 10, 2017 at 8:33 pmHi Kerry.
Looking forward to Trying Out This Recipe =) I wAS Wondering If This Could Easily Be Adapted To Make A Piñata Cake?
Also mY Little Girl Doesn’t Like Fondant Or Buttercream (Or Any Kind) Of Icing, DO You Have Any Suggestions On What Else I Could put In The Layers And What I Could Cover It With? Thank You =)
Kerry Cooks says
September 12, 2017 at 6:36 pmAbsolutely – just use a round cutter to cut the centre out of all the layers except the top and bottom, then fill the gap with sweets 🙂
Re the frosting – you could do melted white or milk chocolate, if she likes chocolate – on the outside. On the inside, maybe fresh cream and strawberries if she likes that? Otherwise, I’m at a loss!
Ruth says
September 10, 2017 at 5:09 pmHi Kerry,
I will make rainbow cake for dd birthday on sunday morning. Would it be ok to bake it on friday night, put it on the freezer. Moving it to the fridge on Sat morning and frosting it in the evening? When i finish decorate it,do i put it back on fridge overnight or leave iy outside? I have bought the foil from wilko, iT’s quite thin. Do i pouR the batter until it full or just half way? Thx
Kerry Cooks says
September 10, 2017 at 5:54 pmHey Ruth – that timeline sounds perfect! When you’re finished decorating, I’d put in fridge, then bring out around an hour before you want to serve.
When you divide the batter into 6, and colour it, you’ll find that each one fills the tin foil cases around half full 🙂 Good luck!
Stella says
August 21, 2017 at 4:12 amCan i use normal All purpose flour or cake flour instead of self raising flour.
Kerry Cooks says
August 24, 2017 at 9:36 amHi Stella – I believe cake flour does not have a raising agent, it just has some corn flour added – so you can’t do that.
Sudha says
June 29, 2017 at 11:06 amHi. HOw much would the batter approximately weigh after adding all the ingredients? Around How much BATTER would be in each cup when divided by 6?
Kerry Cooks says
July 3, 2017 at 8:36 pmHi Sudha – I’ve never weighed it out I’m afraid – it works perfectly well by eye. If you want to work it out that way, you should weigh your bowl, then weight the bowl with batter in and work it out from there 🙂
Carol says
June 3, 2017 at 6:38 pmI am using high quality food COLOURING paste for my rainbiw caKe but cant get A good purple sponge! My purple sponge comes out orange after baking what am i doIng wrong?? Its a lovely colour purple mixture until its cooked then when i cool it and cut tound edge its orange inside!!! Help!!
isabelle says
May 29, 2017 at 10:06 amHello Kerry
just going to make this cake for my daughters birthdays…. I was just wondering if i need to the the frosting the night before(due to lack of time on the day) will it try out overnight in the fridge as im not sure how i would cover it up. many thanks
isabel
isabelle says
May 29, 2017 at 10:07 amgosh my spelling; I mean DRY out!
Kerry Cooks says
May 30, 2017 at 8:48 pmHi Isabelle! You can definitely frost it the night before and leave it in the fridge already frosted, in fact that’s ideal! See my ideal rainbow cake timeline on this page –
Peta says
May 14, 2017 at 6:41 pmHi Kerry sorry if youve Covered this but i couldnt find it, how tall is the cake if i use 8″ tins with 6 layers, once its finished? Im trying to find a bOx that will be tall enough to transport it on a long journey, many thanks
Kerry Cooks says
May 14, 2017 at 8:36 pmHey Pete! No worries at all! 🙂 It will be around 8inch tall with the frosting, so most boxes should do. I’ve taken them on buses and trains with no problem 🙂
Peta says
May 17, 2017 at 2:48 pmThank you !
Peta says
June 8, 2017 at 3:08 pmHello again kerry, ive made your cake and smothered it in the swiss buttercream, Its for a party in two days, do you think i can lay my fondanT on top this eve (thurs) and store it in the fridge til sat? best wishes peta
marchessa says
April 22, 2017 at 11:20 amI’ve used your recipe a few times and each time they’ve come out perfect, thank you! One question, can I use your cheese frosting recipe and put fondant over it? I’ve read that it’s a big no no but I’ve also read as long as it crusts then it’s ok. Can you advise? Thank you!
Kerry Cooks says
April 22, 2017 at 11:57 amHello! Lots of my readers have told me that they’ve done just that and it’s worked perfectly. The only time I might worry is on a really hot day. Good luck!
Rilla says
March 21, 2017 at 1:45 pmHi Kerry
I’m going to make your rainbow cake for my daughters 18th birthday so want to pipe and decorate it up.Do you think I can put roll out icing on top of a thin layer of the frosting so it’s easier to decorate.
Kerry Cooks says
March 22, 2017 at 7:49 pmAbsolutely Rilla! I’ve heard from several people that they’ve put fondant icing on top 🙂
Lisa says
February 20, 2017 at 2:22 pmHelp!Lets start with im rubbish @ working out things,id like to Make a 7 tire cake 7in siZe tin. What wouLd the INGREDIENTS be?Need to make fridAy to DECORATE sat for sun. Thank u so much
Kerry Cooks says
February 21, 2017 at 9:28 pmHi Lisa, you just need to increase the ingredients by 65g for the flour, butter, sugar, and one egg. Enjoy!
Lisa says
February 21, 2017 at 10:33 pmabsolutely amazing thank you Very mich
Lisa says
February 21, 2017 at 10:34 pmVery much
Michelle says
January 21, 2017 at 9:37 amHi kerry, have finally been brave enough to make your rainbow cake. I’be frozen it and am going to DECORATE it today. Does it have to be fully defrosted before I start decorating or can it still be a little bit frozen? Thanks (sorry about the capitals…my phone is playing up!). Xx
Steph says
January 13, 2017 at 3:44 pmHi kerry,
I’M really excited to be making this cake next week! But due to work / children i really only have one day to do it in (and really only 9-3) whilst children in school. Would it be ok to freeze the cakes just for a few hours? I plan to decorate with buttercream. Thank you.
Kerry Cooks says
January 14, 2017 at 3:24 pmHi Steph – absolutely! Even a few hours helps firm it up and make it easier to frost, since freshly baked cakes are so crumbly and easily break. Good luck with the cake!
aimee says
December 10, 2016 at 12:21 pmHI I plan to make this cake for my daughters birthday and was wondering if I make it a couple of days before and freeze it do I take it out the freezer the night before or on the morning of her birthday and do I leave it to defrost before decorating or what works best?
Thanks in advance, Aimee
Kerry Cooks says
December 10, 2016 at 12:31 pmHi Aimee! I’d take it out the night before and then start frosting it first thing in the morning, assuming you want to serve it afternoon or evening 🙂
Aysel says
November 19, 2016 at 10:54 amHi Kerry,
I want to make this cake for my son’s birthday party. But wE will have at least 35-40 people. How can i make it bigger? Will baking it in an 8inch form make it big enough?
Thanks!
Kerry Cooks says
November 20, 2016 at 2:27 pmHi Aysel! This cake will serve a maximum of 15 people, so I suggest you bake some back up cakes as well as the rainbow cake. You could also bake a batch or double batch of rainbow cupcakes – the recipe is here http://kerrycooks.com/easy-rainbow-cupcakes-recipe/
Joan Jones says
November 3, 2016 at 1:59 pmI’m going away 2weeks before my granddaughter’s birthday – can I freeze the cake assembled, and with the frosting And decoration already done
Kerry Cooks says
November 3, 2016 at 8:03 pmHi Joan – you can’t freeze it with frosting on, but you can freeze both the cakes and frosting separately, then defrost a day before if that works for you
Tisha says
August 4, 2016 at 10:14 pmMy blue layer always looks green how do you get yours to look so blue
Kerry Cooks says
August 5, 2016 at 10:05 amHey Tisha, what blue colouring are you using? I use ice blue by sugarflair generally
Lisa says
July 21, 2016 at 1:36 amHi Kerry
I am going to attempt rainbow cake, how many days can I freeze for? I was hoping to do it 4 days before the party?
Kerry Cooks says
July 21, 2016 at 8:38 pmHi Lisa, 4 days is absolutely fine! But you can keep the cakes frozen for up to three months 🙂
Karen says
July 15, 2016 at 12:17 pmHi , i have to make a naked rainbow cake but thd outsides of my cake keep changing color there losing there vibrancy. I was thinking that maybe my oven is to high i cooked them on 180. Any help would be greatly appreciated.
Thanks Karen…
Kerry Cooks says
July 15, 2016 at 4:41 pmHi Karen, just be sure you’re cooking on the middle shelf of the oven and keeping a close eye on them – I rotate them in the oven and make sure that they are cooked, but never browned. Hope that helps!
Lisa says
May 10, 2016 at 12:10 pmHi Kerry…I’m not a baker but will give this a go! My daughter’s not big on frosting other than icing sugar. Will that be sticky enough to hold it all together? Or should I use buttercream in the layers and then icing sugar on the outside? Am going to cover it all in gummy bears! thanks
Kerry Cooks says
May 16, 2016 at 7:07 pmGood luck Lisa! I’m sure you’ll do great. Buttercream should absolutely be stiff enough for the cake, and gummy bears should look really cute!
Lisa says
April 1, 2016 at 5:54 pmHi is the oven temp 170 fan or conventional? Thanks
Kerry Cooks says
April 3, 2016 at 3:15 pmHi Lisa, it’s conventional so take off about 20 if you have a fan oven
Sheena Souza says
February 24, 2016 at 11:24 amWhere will I get my rainbow colours??
Kerry Cooks says
February 24, 2016 at 12:26 pmThere are links in the post to where I buy them from – scroll up!
Carly says
February 10, 2016 at 3:05 pmHi i have cooked this cake a few times before and it has always been a hit 🙂 however I’m going to make it again and I know the recipe just says ‘butter’ is it salted butter you use? I imagine from the recipe that’s what I would have used previously but i can’t remember! Thanks Carly
Kerry Cooks says
February 10, 2016 at 3:36 pmHi Carly! Always unsalted for baking 🙂
Mariyam says
February 9, 2016 at 11:53 pmHi Kerry!
Can you give me the names of the sugar flair colouring you used as I don’t know which ones to get and what colours you used. Thanks
Kerry Cooks says
February 10, 2016 at 9:38 amThey’re in the rainbow cake post!
Leena Web says
February 4, 2016 at 8:08 pmHi I don’t want to used cream cheese just have the buttercream, my kids are picky, so wanted to how much butter and icing sugar I would need
Thank you
Leena
Kerry Cooks says
February 5, 2016 at 9:29 amHello! I don’t make buttercreams as I’m picky and don’t like them, but try googling
Alex says
October 12, 2015 at 3:31 pmHi Kerry,
I ordered ordered Sugarflair cake colour powder the other day, do you think this will work as well as gel? I was hoping it would help with the consistency of the cake as oposed to wet colourings but now i’m worried about how vivid it will be.
kerry says
September 12, 2015 at 1:58 pmHi, i want to make this cake for my boyfriends birthday but I’m so worried that putting the cake in the fridge a lot of times will dry the sponge out ?? thankyou xx
Kerry Cooks says
September 14, 2015 at 11:44 amHi Kerry – there’s no need to worry about that, since it will already be protected by a thin layer of cream cheese frosting the first time it goes into the fridge.
Tara says
September 15, 2015 at 10:00 pmHi, I’ve just baked my cakes and I’m leaving them overnight. Did you trim them down or level them out at all before putting the frosting on? Thanks!
Kerry Cooks says
September 17, 2015 at 1:21 pmHi Tara – mine always come out relatively flat, so I don’t, but if they’re very domed you may want to level them out