This children's book, Cupcake, by Charise Mericle Harper, doesn't come out until January but it looks so cute!
Description from Amazon:
Poor vanilla Cupcake. He's feeling a bit drab next to his fancy friends. But when his new pal Candle comes along with some fresh ideas, the two concoct a plan to become the snazziest duo ever found on a plate!
Harper also did the illustrations for Smart About Chocolate: A Sweet History, by Sandra Markle, which has, yes, a chocolate cupcake on the cover!