The following is, without a doubt, the gayest cake known to mankind: so much so that it's now referred to as "gayke".
I've wanted to make this since the moment I saw Helen's blog on rainbow foods- but what occasion calls for a six-layer rainbow cake? ALL OCCASIONS, actually. This weekend provided an especially festive diversion with two houseguests, so I decided to take the rainbow cake one layer further and top it with bright pink meringue buttercream for extra ridiculousness.
Step one: use every single bowl in my house to divide batter and tint with food coloring. (Things I should've done here: measured out the batter in truly equal increments between the six bowls, and not just eyeball it after several glasses of wine. Oops.)
Step two: make huge batch of meringue buttercream. Frost cake. Run out of frosting halfway through and scamper to make another batch of meringue buttercream to finish the icing shellacking.
Step three: cut into cake while jumping up and down with excitement. Eat cake for every meal.
Notes: I used a basic white cake recipe from The Joy of Cooking for this, and split the batter between six 8" pans rather than the 3" pans called for in the recipe, and reduced cooking time accordingly.
I froze the layers for a few days, which is totally the way to go when frosting a cake. It was practically crumb-free when I spread the frosting over it.
I wanted something fluffier than a standard buttercream, so I used this Sweet Melissa Patisserie meringue buttercream frosting recipe from Epicurious and dumped in red food coloring until the proper level of ridiculous pinkness was achieved. The first batch of frosting used those pasteurized egg whites you can get in a carton, and although they're convenient, they take foreeeeeeeeeeever to whip. The second "oh shit I ran out of frosting" batch of icing was made using egg whites I separated, and it came together much faster.