My baby girl is 3! As per tradition, Anya got to pick out her birthday meal. She picked pink pizza and rainbow cake… just unique enough that I had to think about how to make it work.
I had seen a beautiful, layered cake on Food Gawker
and was in love. Each layer was a different colour with white icing between each layer. I separated and coloured 2 boxes of white cake mix. Since I only own 2 round cake pans, I had to bake 2 layers at a time. Technically, a rainbow has 7 colours (ROYGBIV- red, orange, yellow, green, blue, indigo, and violet) but I decided that purple is purple…I only need 1 purple layer. We bought a big bag of M&Ms to decorate the top of the cake and I think it turned out great!
But the best part of the whole cake was when we cut into it. The kids were amazed by how colourful it was inside and we had a very happy birthday girl.
6 Layer Rainbow Cake
2 boxes white cake mix (mixed according to package directions)
Wilton icing colours (red, orange, yellow, green, blue, purple)
1 pound unsalted butter, room temperature
1 pound vegetable shortening
8-10 cups icing sugar
Preheat oven to 350°. Mix both boxes of cake mix according to package directions. Separate the cake batter into 6 bowls and tint each bowl a different colour. The batter should be a deep colour. Line 9 inch round cake pans with foil and then spray with cooking spray. Bake for 20-25 minutes, until a toothpick inserted into the center of the pan comes out clean. Cool each layer for 5 minutes and remove from pan to a cooling rack.
Meanwhile, prepare icing. Beat unsalted butter and vegetable shortening on high until smooth and completely blended. 1 cup at a time, add icing sugar and mix well between each addition. Continue to add icing sugar until it reaches a good consistency; not too runny, not too thick. Add more icing sugar if necessary or a bit of milk if it becomes too thick. Set aside.
When all layers are completely cool, cut the rounded top off to create a level cake. Starting with the red layer, begin stacking the layers (adding about 1/2 a cup of icing between each layer). Spread the icing evenly to the edge of the cake. Continue to stack the layers (orange, yellow, green, blue, purple). Spread the remaining icing over the top and sides of the cake, covering well.