Fluffy Chocolate Sheet Cake

I forgot to include this recipe the other day with my black forest cakes. It is the recipe I used for the bases. It makes one large, long cake, which can be decorated in the pan and served as a sheet cake, or cut into rectangular pieces and assembled into a four layer torte. Although baked in a jelly roll pan, this cake is too fluffy and fragile to roll into a cake roll. For my black forest cakes, I cut out six circles, about five inches in diameter. This is a high cake, so the layers will be thick. It is not quite a spongecake, but a fluffier and very moist tasty chocolate cake - even plain pieces of it! 

Fluffy Chocolate Sheet Cake
2/3 cup butter or hard margarine, softened
1 cup granulated (white) sugar
3 large eggs
1 1/2 teaspoons vanilla extract
2 cups all-purpose (plain) flour
2/3 cup unsweetened cocoa powder
1 1/2 teaspoons baking powder
1/2 teaspoon baking soda
1 1/3 cups milk

Preheat oven to 350◦F. Grease or line a 10x15 inch jelly roll/sheet pan.
In a large bowl, beat the butter and sugar until creamy. Beat in the eggs and vanilla. Sift together the dry ingredients and add to the butter mixture in three additions, alternately with the milk in two additions  Spread batter in prepared pan. Bake for 20-25 minutes until a toothpick inserted into the center comes out clean. 

Publications International Limited. "Chocolate Mousse Torte." Recipe. Hershey's Classic Recipes, Lincolnwood Illinois: Publications International, Limited, 2000. 25.