This is the most beautiful cake to make and even better to eat and I’m really excited to be sharing it with you. The first thing to note is that my picture is from my first attempt. There are many reasons why it looks slightly wonky and why it’s pastel in colour – I’ve written some tips at the bottom of the recipe for ways to make it look practically perfect in every way.
Now, it was a revelation making this cake, not just because it is so pretty but also because I tried a new way of making sponge – to weigh the eggs then add exactly the same amount of flour, sugar and butter. I would normally use a ratio of three eggs to 6oz flour, sugar and butter, but this way makes a lighter sponge and I think it was well worth it. Enjoy!
- 4 eggs (weighed with their shells on)
- Equivalent weight of plain flour, sugar and butter (see method below)
- 2 tsp baking powder
- 1 tsp vanilla extract
- At least four types of food colouring
Icing and middle:
- 250g icing sugar
- 80g butter
- 25ml milk
Weigh the eggs in their shell. Use exactly the same amount of butter, sugar and flour as the eggs weigh (in my case it was 246g). Set the oven to 180C. Butter and line a cake tin or four.
In a blender, mix together the butter and sugar until light and fluffy.
Add the eggs, one at a time, until combined.
Mix in the flour and baking powder, a couple of tablespoons at a time, until combined and smooth.
Add the vanilla extract and mix until smooth. Do not overmix.
Divide the cake mixture into four equal parts using a set of scales. Add a different food colouring to each bowl and don’t be shy – make the colour as vibrant as possible.
Bake each very thin cake in the same size of cake tin. You can keep reusing the same cake tin if you only have one.
Bake in the oven for 15-20 minutes. Keep checking – it will depend on how big your tin is as to how long to cook it for. It’s done when the cake comes away from the sides a little and when it springs back when you gently press it with your fingers.
While the cake is cooling, mix up the icing by chucking the lot into a blender and mixing it til smooth. Set aside.
Stack the cooled cakes up with icing in the middle any which way you want.
Gel food colourings make a stronger colour than regular liquid ones. I used liquid ones and they gave a pastel effect.
My cake is a little wonky because I didn’t use the same cake tin each time!
I’ve seen beautiful versions of this cake with a white icing all over it, and a dusting of hundreds and thousands.
Search google images for ‘Rainbow cakes’ to see other great ways to decorate them.
Add another egg and turn it into a five tier cake, or another and make it six!
The sky’s the limit – with seven cakes you can do a full rainbow.