My youngest son Ben turned 17 today. He is fascinated with mushrooms, so we made him a mushroom cake. Actually a trio of cakes:
It looks a bit like cupcakes, but no cupcakes were harmed in the making of this cake.
The main mushroom has a stem ("It's called a stipe, Dad") made of two 4.5-inch cake rounds. The cap ("pileus, Dad") was baked in the bottom of a stainless steel mixing bowl. The two stem pieces bulged more than we expected, so we sliced them off and made caps for the medium mushrooms. They are supported by stacked Ring-Dings for the stem.
The dots are mega M&M's. The tiny mushrooms are mini-marshmallows supporting white chocolate Reese's peanut butter cups. Gummi worms add character.
A cut-away view of the medium mushroom: