Sponge

1. Preheat the oven to 160°C fan. Lightly grease and line three 4 inch round cake tins (or two 6 inch tins) with baking paper.
2. Cream together the caster sugar and baking spread in a bowl for 2 mins, until light and fluffy.
3. Add the eggs, oil and vanilla extract, along with a large spoonful of the flour and beat together.
4. Fold the remaining flour into the mixture with the milk, using a spatula/metal spoon.
5. Divide the mixture in 3 and add your chosen food colouring to each.
6. Add equal amounts of the mixture to each tin by randomly adding spoonful’s of each colour.
7. Using a knife or skewer, swirl the colours together and then bake in the oven for 25-30 mins.
8. Leave the sponges in the tins for 10 mins, then remove and cool on a wire rack.

Buttercream

1. With a handheld or stand mixer, beat the butter for 2-3 mins until pale and fluffy.
2. Add a third of the icing sugar and beat again until combined. Repeat for each third of the icing sugar.
3. Add the vanilla extract and milk and beat the buttercream for 5 mins. If you are working in a warm environment, less milk may be required.
4. Take a quarter of the buttercream, cover it with cling film and set aside. You will be colouring and using this later.

Decorating

1. Assemble the cake by adding a thin layer of buttercream to the first sponge. Then add a thick ring of buttercream around the edge and fill the centre with half the jam. Add the next sponge and repeat, then place the third sponge on top.
2. Cover the cake with a thin crumb coat (layer of buttercream covering the whole cake). Place the cake in the fridge for at least half an hour to chill.
3. Once the crumb coat is firm, cover the cake with the remaining uncoloured buttercream, using a palette knife or straight edged cake scraper to smooth it. Put the cake back in the fridge for at least an hour.
4. When you are almost ready to decorate the cake, take the buttercream you set aside earlier and split it into 3.
5. Colour the buttercream with your chosen colours.
6. Using a 9 inch palette knife and starting two thirds of the way down the cake, take a small amount of buttercream and smear it on the cake in an upwards direction.
7. Repeat this by randomly using the different colours and work your way up the cake, finishing in the centre of the top of the cake.

Tips

1. If you don’t have 4 inch cake tins, this recipe will make a two layer 6 inch cake.
2. By folding in the flour for your sponge mix with a spatula or metal spoon, this ensures the air bubbles in the mixture are retained and it will help make your cake mixture light.
3. You can use unsalted butter instead of baking spread for the sponge, just make sure the butter is at room temperature.
4. Cover your buttercream with cling film when you are not using it to stop it crusting on top.
5. The firmer the cake for each buttercream step the better.