This rainbow cake recipe is such a great way to bring some fun to a party or event. Its slightly more complicated than a Victoria Sponge recipe, but only because of the number of layers. The brightly coloured inside can be hidden as a surprise or decorated on the outside in just an exuberant way as the inside. I’ve made this cake a number of times and it is still just as fun to reveal the inside as it was the first time.
If you want to add an extra surprise to the centre of the cake, you can cut a small hole in the centre of all the layers except for the top layer, and once stacked, you can fill the hole with sweets. Add the top layer and ice the cake as normal. This adds a cascade of colourful sweets from the centre of the cake when the first slice is cut.
12oz caster sugar
12oz self raising flour
1 1/2 tsp vanilla extract
Food colouring (I use the paste, over the liquid or gel, as it is easier to get a strong colour in the sponges)
Pre-heat the oven to gas 6/200 degrees/180 fan. Grease and line 2 8-inch round tins.
Measure out 4oz of butter and 4oz of sugar and beat together until the mixture is light and fluffy (this takes about 3-4 minutes with a wooden spoon and about 2-3 minutes with an electric mixer).
Measure out 4oz flour and set aside.
Beat in 2 eggs and 1/2 teaspoon of vanilla well.
If the mixture appears curdled at this stage, add in a tablespoon of the flour.
Once all combined, stir in the flour (careful not to beat at this stage otherwise you can knock out the air and the cakes may not rise properly).
Split the mixture into 2 bowls and add a different colouring to each bowl and mix through. You want to make sure the colour is bold as it can get lighter as it bakes.
Bake in the oven for 10- 15 minutes, until the top is springy and the cake starts to come away from the sides of the pan. Leave to cool in the pan for 5 minutes and then turn out onto a wire rack to cool.
Repeat the above process twice more until you have 6 layers, all in different colours. If you happen to have more than 2 tins and your oven is large enough to fit them in all at once, then you can of course bake more layers at the same time.
Tip: This recipe means that the layers are thinner than a usual Victoria Sandwich cake, but this allows for 6 layers rather than 2! It will still be taller than a usual sandwich cake.
Once all the layers have been baked and cooled, mix up some buttercream icing using 8oz icing sugar, 4 oz softened butter and a little milk. Combine the butter and sugar until you have a stiff mixture. You may need to add more icing sugar if too wet or milk if too stiff but you are looking for icing which holds its shape and doesn’t run off a spoon. You can also flavour with a little vanilla extract if you wish.
Wipe a small amount of the icing on the serving plate to ‘stick’ the cake to it and stopping it from sliding about. Layer up the cakes using a thin layer of the the icing as a ‘glue’ between each layer (to avoid it being too sweet, I keep the icing to a minimum between each layer).
Once all the cakes have been stacked, I prefer to ice the whole of the outside so that the inside is kept a surprise until the first slice. You can do this using either the buttercream or fondant icing (coat the cake with a thin layer of buttercream first to give the fondant something to stick to). You can also cover the buttercream covered cake in sprinkles for a little extra fun.