1/2 cup Hershey's cocoa
1/2 cup boiling water
1/4 cup (1/2 stick) butter or margarine, softened
1/4 cup shortening
2 cups granulated sugar
1/8 teaspoon salt
1 teaspoon vanilla extract
2 eggs
1 1/2 teaspoons plus 1/8 teaspoon baking soda, divided
1 cup plus 3 tablespoons buttermilk or sour milk, divided*
1 3/4 cups all-purpose flour
3/4 teaspoon freshly grated orange peel
1/4 teaspoon orange extract
Orange Buttercream Frosting

Preheat oven to 350 degrees F. Grease three 8- or 9-inch round baking pans; line with wax paper.

Stir together cocoa and water in small bowl until smooth; set aside. Beat butter, shortening, sugar, salt and vanilla extract in large bowl until well blended. Add eggs; beat well. Stir 1 1/2 teaspoons baking soda into 1 cup buttermilk; add to butter mixture alternately with flour.

Measure 1 2/3 cups batter into small bowl; stir in remaining 1/8 teaspoon baking soda and 3 tablespoons buttermilk, orange peel and orange extract. Pour into one prepared pan. Stir cocoa mixture into batter; divide evenly between remaining two prepared pans.

Bake 25 to 30 minutes or until wooden pick inserted in center comes out clean. Cool 10 minutes; remove from pans to wire racks. Carefully peel off wax paper. Cool completely.

Place one chocolate layer on serving plate; spread with Orange Buttercream Frosting. Top with orange layer; spread with frosting. Top with remaining chocolate layer; frost top and sides of cake.

Yield: 10 to 12 servings

*To sour milk: Use 1 tablespoon white vinegar plus milk to equal 1 cup; use 1/2 teaspoon white vinegar plus milk to equal 3 tablespoons.

Orange Buttercream Frosting
2/3 cup butter or margarine, softened
6 cups confectioners' sugar, divided
2 teaspoons freshly grated orange peel
1 1/2 teaspoons vanilla extract
4 to 6 tablespoons milk

Beat butter, 1 cup confectioners' sugar, orange peel and vanilla extract in large bowl until creamy. Add remaining confectioners' sugar alternately with milk, beating to spreading consistency.