Rainbow Cake Recipe

It’s been the Pride in London celebrations this weekend, so a great excuse to make a rainbow coloured cake. Everything you need to know to make a lemon funfetti cake like this for yourself is on this week’s blog.

No blog from me last week as I had a late night back from sea fishing off the coast of Lymington in Hampshire. It was honestly one of the best day’s fishing I’d ever had with my Dad and it reminded me of the incredible fishing trip we took together to Alaska 16 years ago. One day we’ll return! There’s nothing like being so far out in the sea that you have no phone reception, complete tranquility, and obviously the bonus of catching loads of fish. My wife Sarah doesn’t eat fish but thankfully she was away on business last week, so me and the kids went over to my parents’ house for a feast of barbequed mackerel and skate on Monday.

I’ve had such a hectic week at work and with baking in the evenings that we missed out on Chetna Makan‘s book launch for ‘Chai, Chaat & Chutney’ on Thursday night. We had it in the diary for next week by mistake so instead of spending a hot summer’s evening eating great food and drinking beer with my Bake Off buddies, I was up to my elbows in flour making the cake at the top of this blog post. Chetna is easily the best cook we’ve had on the Bake Off – eating at her house is such a treat. Her new book, available here, is a beauty and we’ve already started earmarking recipes to try.

Every year since Bake Off I make a cake for my kids’ school summer fair for the ‘Guess The Weight of the Cake’ competition. As the fair was yesterday, the same day as the Pride celebrations in London, I made a rainbow-themed cake (which weighed 3856g if you’re interested). It was four layers of funfetti lemon sponge sandwiched with lemon curd and lemon buttercream, and covered in rainbow tie-dye fondant. ‘Funfetti’ means a sponge or biscuit with coloured sprinkles through it, but with many sprinkles the colours run so the ones I’ve referenced below are the best I’ve ever used. It was then topped with rainbow meringue kisses (the remaining baking parchment is above) and royal icing stars. Here’s how you can make it yourself.

Rainbow Cake Recipe


For 2 x 10″ sponges

  • 8 large eggs
  • 450g unsalted butter
  • 450g caster sugar
  • 450g plain flour
  • 4.5 tsp of baking powder
  • zest and juice of 2 lemons
  • 6 tbsp of coloured sprinkles / 100s and 1000s (I use these as the colour doesn’t run. This big bag has lasted me ages)

For the buttercream, meringues and decoration

  • 500g icing sugar
  • 250g unsalted butter
  • juice of 1 lemon
  • 3 heaped tbsps lemon curd (from a jar, or if you want to make lemon curd from scratch, see here)
  • 1.5kg white fondant
  • 500g royal icing sugar (for example, this)
  • gel colourings (I use these Wilton colours)
  • 2 egg whites
  • 110g caster sugar
  • 1/4 tsp of cream of tartar (if you’ve got it)
  • Silver balls or other decorations you fancy using


  1. N.B. I only have one 10″ cake tin so I made this cake in two batches
  2. Grease and line your tin with baking parchment
  3. Pre-heat the oven to 180oC  / fan 160oC  / gas mark 4
  4. For the sponges, cream together 225g butter and 225g caster sugar with an electric hand whisk
  5. Beat 4 eggs into the mix then add the zest and juice of one lemon
  6. Mix 2 1/4 tsp baking powder and 3 tbp of coloured sprinkles into 225g plain flour
  7. Gently fold these dry ingredients into the mix with a silicone spatula – don’t over-mix or the colour can run in your sprinkles
  8. Put the mixture into your tin, smooth the surface and bake for 40 minutes. When a cocktail stick comes out clean from the centre of the cake, it’s done
  9. Allow the sponge to cool in its tin for 10 minutes before taking it out and putting it on a cooling rack
  10. Repeat all of the steps above for the second sponge
  11. To make the meringue kisses, in a clean bowl (preferably a glass or metal bowl) beat two egg whites and a 1/4 tsp of cream of tartar until they’re at ‘soft peaks’ stage (this means they just about hold their shape but flop over when the beaters are lifted)
  12. Tip in half of the sugar and continue beating with an electric hand mixer until it’s glossy and stiff then fold the rest of the sugar in with a metal spoon
  13. Add a big star-tipped nozzle to a piping bag. Take four cocktail sticks and your four gel colours and smear a line of each colour inside your piping bag. Drop the meringue mixture in to the piping bag and then pipe the small meringue kisses onto a baking tray lined with baking parchment
  14. Bake these in a pre-heated oven (preferably NOT a fan assisted oven) at 110oC  / fan 90oC  / gas mark 1/4 for 90 minutes
  15. To make the buttercream, beat 500g of icing sugar with 250g of softened unsalted butter and 3tbsp of lemon juice to flavour it and loosen it up
  16. I used my cake cutter to cut each sponge in half horizontally so that there were four thin layers in the cake. If you don’t have a cake cutter, you can use a large bread knife (watch your fingers!) or just have two layers instead
  17. Construct the cake by smoothing buttercream onto the first sponge, then pipe an additional ring of buttercream around the edge of the first sponge. Spread a heaped tablespoon of lemon curd in the well made by the ring. The buttercream ring stops the curd from oozing out of the cake
  18. Smooth more buttercream onto the bottom of the second sponge and sandwich this on top. Repeat until you have four layers of cake, then spread a smooth layer of buttercream all around the cake
  19. For the tie-dye effect fondant, colour about 125g of fondant in each of the colours you’re using – so I had 125g of red, 125g of yellow, 125g of green and 125g of blue and roll these into sausages of about 50cm long
  20. Roll 1kg of white fondant into a thick sausage of about 50cm long. Wind all of these together, twist and roll out a few times until the colours are incorporated but NOT mixed
  21. Roll the tie-dyed fondant out and cover your cake
  22. Mix four colours of royal icing in four separate bowls, with 125g of icing sugar in each bowl and a little boiling water. Use icing nozzle couplers (e.g. these) if you have them and dig out all your different nozzle shapes
  23. Arrange your meringue kisses and pipe different colour and shaped stars all over the top of the cake and around the bottom edge. Finish with silver balls

I used rainbow colours for this but it would be just as effective with two or three different colours. If you give it a go, let me know and if any of this doesn’t make sense, do get in touch! I’ve got another massive cake to make this week with more tips to follow so until next week, Happy Baking!

One thought on “Rainbow Cake Recipe

  1. Pingback: Perfect Chocolate Cake Recipe | Richard Burr

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