For a double birthday for my two and four-year-old kids. The party theme was getting messy, and one of the party activities was painting. I let the kids paint on a "canvas" of rolled fondant with edible "paint" made from thinned icing, then attached it to the cake and added a palette I made out of gum paste and royal icing. The kids loved that they got to paint and put their own hand prints on their cake.