Friday, 15 July 2011

Making Your Own Rainbow Cake

So, you'd like to make your own rainbow cake? Great! (If you have no interest whatsoever, you're still allowed to read this post. Just don't tell too many people about your lack of interest or they might think you're weird. Who wouldn't want to make a cake as cool as this one? Don't answer that.)

Someone else might have a much more straightforward tutorial for you, but this is how I made mine.

First, choose a plain vanilla sponge recipe which works for you, and double the quantities.

What you'll need:
1-5 round baking tins (depending on what shape you want it and how many layers you'd like) of equal size
Food colouring (I chose yellow, green, blue, purple and pink)
Cling film/plastic food wrap (or whatever you want to call it)
Ingredients for the cakes
Buttercream icing
Lemon curd or apricot jam (adds a little something to the layers but the light colour doesn't interfere with the carefully thought-out colour scheme)

So, here's the recipe I used (I've doubled the quantities, which makes 6 layers):

8 eggs
450g unsalted butter, at room temperature
450g caster sugar
420g self-raising flour, sifted
50g cornflour
2 teaspoons baking podwer
2 teaspoons vanilla extract
6 tablespoons milk

Preheat the oven to 180 degrees C (or 160 for a fan-assisted oven).

Line each baking tray with greaseproof paper and spread a thin layer of butter around the inside (this will help the cakes to pop out easily after baking).

In a mixing bowl, cream the butter and sugar with an electric hand mixer until the mixture is pale and smooth. Mix the dry ingredients in a separate bowl. Add the eggs and dry ingredients to the wet mixture, alternating between the eggs and dry mixture, mixing well after each addition. Add the vanilla extract and milk. Don't over-beat the mixture or you'll take the air out of the cakes. Apparently. I don't know.

Divide the mixture equally into 6 bowls (one bowl for each layer). One bowl at a time, add food colouring to the cake mixture, stirring well. Add as much food colouring as you like.

Pour each bowl of cake mixture into its own baking tin. I only had 3 baking tins the same size, so I baked 3, then washed them up and used them again. You didn't need to know that but I just wanted to remind you that you don't need to go out and buy 6 baking tins.

Bake in the oven for about 25 minutes until raised and and golden brown. The whole 'golden brown' thing may be difficult to read with all of the food colouring, so stick a skewer into the centre of one of the cakes. If it comes out clean, the cake is cooked. When I say clean, I mean no uncooked cake mix on there. Don't go sticking a dirty skewer in there, thinking it'll magically come out clean when the cake is cooked.

Allow the cakes to cool in their tins for about 10 minutes before turning them out onto a wire rack to cool. Remove the greaseproof paper from the bases of the cakes.

At this stage, the cakes probably won't look that appealing. The green and blue cakes will probably look a bit mouldy. Don't be discouraged, my friend. It'll look great once it's cut into. Well, it should. I can't be held responsible for any baking failures.

 [To encourage you: check out the dodgy look of the outside of this cake. Concerning, right? Oh, but break it open and it's bright and magical.]

Before assembling this cake, a word of advice:
This cake doesn't transport well if you want the cake to not look like the leaning tower of Pisa. If you're planning on taking this cake to a party or the zoo or something, you may prefer to assemble it there. In which case, wrap each sponge cake in cling film (make sure they've fully cooled). This will stop the cakes from sticking to each other.

Time to assemble the cakes.

Arrange them into the colour order you'd like. Spread the lemon curd onto the top of the first layer of the cake. On the underside of the next layer, spread the buttercream icing and lower onto the first layer. Repeat with each layer. Unless you really don't want any jam-type stuff, in which case just stick with the buttercream.

Cover the outside of the cake with buttercream and decorate with sweets, if you want.

Have you done it yet? Leave me links to your cakes!


  1. Love it! This is perfect for a children's birthday party. The kids would get a kick out of the colors inside! ~Val

  2. SO COOL!! Glad to see you back in the blogosphere, and with such a cheery post :)