For my mother's birthday, instead of baking one rectangle cake I made 2 circle cakes and had 2 of my neices, K and B, decorate it. Each girl got their own container of frosting, and a huge assortment of sprinkles to decorate with. They had a blast decorating, and when the time came for cake they made sure that each person knew who had decorated what cake (although by that time neither one could remember which cake they decorated and they actually pointed out the other girl's cake as their own LOL). The bigger people at the party told the girls how awesome their cakes looked and tasted...you should have seen their smiles!!