Chocolate Marshmallow-Ghost Cake and Mini Cupcakes

Preheat oven to 350 degrees. Butter three 6-inch round cake pans. Dust with cocoa powder, and tap out excess; set aside. Alternatively, line six mini muffin tins with paper liners.

Whisk together flour, cocoa powder, baking powder, and salt in a medium bowl. Put butter and sugar into the bowl of an electric mixer fitted with the paddle attachment. Mix on medium-high speed until pale and fluffy, about 4 minutes. Add eggs, one at a time, mixing until combined after each addition. Mix in vanilla.

Reduce speed to low. Add flour mixture in three batches, alternating with the milk. Mix until just combined. Divide batter evenly among pans (about 2 cups batter per pan) or lined muffin cups (about 1 tablespoon batter per cup).

Bake until a cake tester inserted into centers comes out clean, 30 to 40 minutes for cake layers and 14 to 16 minutes for mini cupcakes. Let cool in pans or muffin tins on a wire rack. Decorate as desired.