I like this cake idea to make a PINATA. Rainbow Cake / Cupcakes - would be pretty, even if we only used 3 or 4 color layers (Red, pink, purple, turquoise?) to go with Elmo/Abby theme!
Easy 6-Layer Rainbow Cake
It's honestly so easy to make a Rainbow Cake using this tutorial - just check out the comments at the bottom of the recipe! Must-have birthday cake, perfect for kids parties. It's actually a super simple recipe and it's all covered in loads of the most delicious cream cheese frosting for an amazing tasting Rainbow Cake!