Chocolate Sheet Cake I - cooking recipe

Ingredients

2 cups all-purpose flour
2 cups white sugar
1 teaspoon baking soda
1 teaspoon ground cinnamon
1/2 teaspoon salt
1/2 cup margarine
1/2 cup shortening
1/4 cup unsweetened cocoa powder
1 cup water
2 eggs, beaten
1/2 cup buttermilk
1/2 cup margarine
6 tablespoons milk
1/4 cup unsweetened cocoa powder
1 teaspoon vanilla extract
4 cups sifted confectioners' sugar

Preparation

Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 10x15 inch jellyroll pan. In a large bowl, sift together the flour, sugar, baking soda, cinnamon and salt. Set aside.
In a saucepan combine 1/2 cup margarine, shortening, 1/4 cup cocoa and water. Bring to a boil and cook for 1 minute. Pour the liquid mixture over the flour, sugar mixture; stir well. Blend in eggs and buttermilk.
Pour batter into prepared pan. Bake in the preheated oven for 30 minutes, or until a toothpick inserted into the center of the cake comes out clean. Let cake cool 10 minutes, then frost while still warm.
To make the Frosting: In a saucepan combine 1/2 cup margarine, milk and 1/4 cup cocoa. Bring to a boil and cook for 1 minute. Remove from heat and stir in vanilla. Mix in confectioners' sugar. Pour over warm cake