For Clare's 6th birthday I made my first attempt at a "rainbow cake." It was very easy to make and the end result was so neat! (I impressed Ryan quite a bit!)
You will need 2 boxes of cake mix and 2 - 3 containers of icing.
Mix up the cake mix according to package directions. I divided the cake batter into separate bowls and added food coloring to each bowl to make all 6 colors: red, orange, yellow, green, blue, and purple. To make each layer of the cake the same thickness, I put about 1 1/3 cup of batter into each bowl.
I baked 3 cakes at a time (that's all the cake pans I had). They baked at 350 for 25 minutes.
Cool the cakes and begin assembling the cake by staking and icing the layers together.
Ice the entire cake...I only used 2 containers of icing, but I think I could have used 1 more to cover the cake a little better. And we even topped it with rainbow sprinkles!
The surprise is when the cake is cut...so neat! Clare said she'll remember this cake until she's 10!