Whoa! My e-mail box overfloweth more than usual … all about the rainbow cake! I love that one too. Every time I look at it, it just puts a big smile on my face. How could it not with those bright, vibrant happy colors? So to answer the questions in one big swoop, here are a few notes:
* The cake recipe? Two boxes of white cake mix. Total cheat city. But you know what? That’s ok. With this type of cake, where there are other details and things to take care of, I think it’s perfectly fine to cheat. I happened to use Pillsbury (with pudding in the mix), but am sure any would do, as would a cake from scratch, of course.
* Follow the directions on the cake mix, mixing the two boxes and associated ingredients together in one big bowl. Divide the batter amongst six bowls so you can color the batter.
* Now for the color. For these vibrant colors, you can’t use regular food coloring because it produces more pale colors. You need icing color, which is much more concentrated (Wilton makes some, for example). You need lots less and it goes far. You can find it in cake decorating aisles of stores like Michael’s and AC Moore (usually sold in a small box of 8-10 small containers of different colors). You really need just a speck or two of the color in each bowl. Add more as desired to get the shade you want.
* Put the batter into six round cake pans that have been lightly greased. It worked out to roughly 1-1/4 cup of batter in each pan.
* Bake at the oven temperature specified for your particular mix, but because the layers are a bit smaller, the time in the oven needs to be adjusted. Start checking the cake at about 12 minutes. Mine were done at around 14 minutes.
* While the cakes are cooling, make your frosting. When the cakes are cooled, cut off a thin bit of cake from each top so your layers are very flat. Since they tend to dome a smidge when baking, if you don’t level it a bit, the cake will topple over in no time flat since we’re building it so high.
* For the frosting, I used buttercream, my favorite. I spread a thin layer of frosting in between each cake layer, and then all over the tops and sides.
P.S. You can find the original Rainbow Cake post here, along with more pictures.