My friend's daughter turned 5 recently, and there was much debate as to how she wanted the cupcakes decorated. Ultimately, she decided on vanilla/vanilla cupcakes with rainbow sprinkles. Since I was making two dozen cupcakes for her friends at school, I thought making the whole box into a rainbow would be fun. But five-year-olds are funny little things, and I didn't want the birthday girl to be disappointed if her cupcake wasn't actually a rainbow. So I made a special cupcake, just for her, rolled in concentric circles of rainbow sanding sugar. I threw on some rainbow flower sprinkles to make it extra girly and fun.