I do them so infrequently I forget how much cake batter they take. Anybody know?

I need to make the skirt and then (2) 8" layers for an actual Barbie not doll pick right?

A Wonder mold pan takes enough batter for a 2 layer 9in round cake. And yes, if using an actual barbie doll, not a pick, you will need to make it taller with extra rounds underneath.