2 cups unsifted all-purpose flour
1 1/2 cups sugar
1 teaspoon baking soda
1 teaspoon baking powder
1/2 teaspoon salt
1/4 cup butter or margarine. softened
1/4 cup shortening
1 1/2 teaspoons vanilla
1 1/4 cups buttermilk or sour milk
4 egg whites (reserve 2 egg yolks for fillings)
Cream Filling (see below)
Chocolate Glaze (see below)
Grease and dust with flour two 9 inch layer pans. Combine flour, sugar, baking soda, baking powder and salt in large mixer bowl. Add butter, shortening, vanilla and buttermilk. Blend on low speed 30 seconds; beat on medium speed 2 minutes. Add egg whites; beat 2 minutes. Pour into pans and bake at 350 degrees for 30 to 35 minutes, or until cake tester inserted in centers comes out clean. Cool 10 minutes; remove from pans. Cool completely.
Prepare Cream Filling. Spoon onto 1 cake layer. Carefully top with remaining layer. Prepare Chocolate Glaze. Immediately pour onto top of cake, allowing some to drizzle down side. Chill before serving.
Combine 1/3 cup sugar, 2 tablespoons cornstarch and 1/8 teaspoon salt in saucepan. Gradually add 1 1/2 cups milk and reserved 2 egg yolks; blend well. Cook and stir over medium heat until mixture boils; boil and stir 1 minute. Remove from heat; blend in 1 tablespoon butter and 1 teaspoon vanilla. Cool 10 minutes.
Combine 3 tablespoons water and 2 tablespoons butter in small saucepan. Bring to full boil; remove from heat and add 1/4 cup Hershey's Cocoa. Stir until mixture leaves side of pan and forms ball. Beat in 1 cup powdered sugar and 1/2 teaspoon vanilla until smooth.
To Sour Milk: Use 1 tablespoon plus 1 teaspoon vinegar plus milk to equal 1 1/4 cups.
Makes 8 to 10 servings.