A picnic favorite, this chocolate sheet cake has white chocolate frosting with a decorative semisweet chocolate drizzle.

Take-Along Picnic Cake

Cake:

1 cup water
1 cup butter
1/2 cup unsweetened cocoa powder
2 cups granulated sugar
1 3/4 cups all-purpose flour
1 teaspoon baking soda
1/2 teaspoon salt
3 large eggs
3/4 cup sour cream

White Chocolate Frosting:

1/3 cup butter
1/3 cup milk
1 2/3 cups white chocolate chips
1 teaspoon vanilla extract
1 cup powdered sugar

Chocolate Drizzle:

1/2 cup semisweet chocolate chips

1 teaspoon vegetable shortening

1. Heat oven to 350°F (175°C). Grease and flour 15 1/2 x 10 1/2 x 1-inch jelly roll pan; set aside.
2. For Cake: Combine water, butter and cocoa in medium saucepan. Cook over medium heat, stirring occasionally, until mixture boils. Boil 1 minute. Remove from heat; set aside.
3. Stir together sugar, flour, baking soda and salt in large bowl. Add eggs and sour cream; beat until blended. Add cocoa mixture; beat just until blended (batter will be thin). Pour into prepared pan.
4. Bake 25 to 30 minutes or until wooden pick inserted in center comes out clean. Cool cake in pan on wire rack.
5. For White Chocolate Frosting: In a medium saucepan, combine butter, milk and chocolate chips and cook over low heat, stirring constantly, until chips are melted and mixture is smooth. Remove from heat and stir in vanilla. Place powdered sugar in medium bowl and gradually add chocolate mixture, beating until well blended. Cool, stirring occasionally, until of spreading consistency, about 1 hour. Spread over top of cake.
6. For Chocolate Drizzle: Melt chocolate chips and shortening in small microwave at HIGH (100%) for 1 minute; stir until chips are melted and mixture is smooth. Drizzle decoratively over frosting.

Makes about 20 servings.