Directions

1. Pre-heat your oven to 180°C (160 °C Fan assisted)/Gas Mark 4. Grease and line the bases of your 7 inch cake tins. Place both cake mixes into a mixing bowl along with 360g of soft butter (or dairy free alternative), 6 eggs and 40ml of water. Using an electric mixer, mix the ingredients for 15 seconds. Then stop, scrape down the sides of the bowl with a spatula and mix again for another 10 seconds.

2. Divide the mix equally into 6 bowls, adding ½ a teaspoon of Wilton colouring into each bowl – you should have six different coloured bowls all together.

3. Pour two of the bowls into two of your cake tins, and bake for 18-20 minutes. Before you take the layers out of the oven, check that the cake is golden brown, or insert a skewer into the centre of the cake and check it comes out clean. Once out of the oven, leave the cakes to cool for 5 minutes before you take them out of the tins. Repeat this step with the rest of your bowls until all 6 layers are baked.

4. Mix the remaining 450g of butter (or dairy free alternative) with the icing sugar and the vanilla extract in a bowl until thoroughly mixed.Place the violet layer of the cake onto the base of a cake board or large plate, then spread some of the icing over the top with buttercream. Place the blue cake layer on top of this, and repeat the process following the order: violet, blue, green, yellow, pink and red. Or alternatively, you could mix it up! Once all the cakes have been layered with buttercream, cover the rest of your cake with the remaining buttercream.