10" inch and total of 6 cake/brownie layers! Buns are vanilla cake filled with brown sugar smbc and chocolate chip cookie dough balls. Cakes also frosted in the same brown sugar smbc. I used a plastic tool (cut out from soda bottle, lol) to shape and smooth the dome on top bun. The burger is two layers of chocolate brownie filled with an instant fudge frosting. Decorations are all made of marshmallow fondant.