Bake at 350° for 20 to 25 minutes or until a wooden pick inserted in center comes out clean. Remove from oven; top warm cake evenly with marshmallows. Return to oven, and bake 5 minutes. Drizzle Chocolate Frosting over warm cake. Cool completely.
1 (16 oz) package powdered sugar, sifted
1/2 c. milk
1/4 c. butter, softened
1/3 c. unsweetened cocoa