3 x 340 g packet golden butter cake mix
pink food colouring paste
orange food colouring paste
yellow food colouring paste
green food colouring paste
blue food colouring paste
mega-sized candy-coated chocolate bits or gumballs, to decorate
600 g unsalted butter, chopped, at room temperature
5 ½ cups icing sugar mixture
- Grease two 22cm round cake pans. Line bases and sides with baking paper.
- Prepare one cake mix according to packet directions. Divide in half. Tint one half pink. Spoon into one of the prepared pans. Tint remaining cake mix orange. Spoon into remaining prepared pan. Smooth tops.
- Cook both cakes in a moderate oven (180C) for 15 to 20 minutes, swapping pans halfway through cooking, until lightly browned. Stand for 5 minutes. Turn out onto a wire rack to cool.
- Wipe pans clean. Grease and re-line. Repeat with remaining two cake mixes to make yellow and green cakes and blue and violet cakes. To make the violet food colouring, mix red and blue until desired colour is met.
- To make butter frosting, beat butter in a large bowl of an electric mixer until light and fluffy. Gradually add icing sugar, ½ cup at a time, beating until smooth.
- To assemble cake, place violet cake on a cake board. Spread with ½ cup frosting. Repeat layering with blue, green, yellow, orange and pink cakes, spreading ½ cup frosting in between each layer. Spread remaining frosting over top and side of cake. Decorate top with gumballs.