2 cups sifted all-purpose flour
1 cup granulated sugar
1 cup dark brown sugar
1 cup unsweetened cocoa powder
1 1/2 teaspoons baking soda
1 cup Dr. Pepper
1/2 cup chocolate chips
2 large eggs
1 cup buttermilk
1 cup vegetable oil
1 1/2 teaspoons vanilla extract

Frosting
3/4 cup butter-flavored vegetable shortening
6 tablespoons unsalted butter, softened
4 cups sifted confectioners' sugar
1/4 cup unsweetened cocoa powder
1/4 cup Dr. Pepper
1 1/2 teaspoons vanilla extract

Preheat oven to 350 degrees F. Grease and flour two 9-inch round cake pans, tapping out any extra flour.

Sift together flour, granulated sugar, brown sugar, cocoa and baking soda into a bowl and set aside.

Pour the Dr. Pepper into a saucepan and add the chocolate chips. Heat on low, stirring often, until the chips are just melted. Remove from heat and set aside.

Combine eggs, buttermilk, oil and vanilla extract in a mixer bowl and mix on medium speed until combined, about 2 minutes. With the mixer running, slowly pour in the Dr. Pepper-chocolate mixture and continue beating until combined, about 1 minute.

With mixer on low, gradually add the dry ingredients. Increase speed to medium and beat 2 minutes more. Divide the batter between the 2 pans. Bake for 30 to 35 minutes or until a wooden pick inserted into the center comes out clean. Cool the layers in the pan for 10 minutes, then run a knife around the edges and flip the pans over onto a cooling rack. Gently lift off the pans and let the cake layers cool completely.

To make frosting, beat shortening and butter in a mixer bowl until soft and fluffy. Add the confectioners' sugar and cocoa, and continue mixing until combined. Stir together the Dr. Pepper and vanilla extract and very slowly pour it into the frosting, beating with mixer on high speed to thin it a bit. Continue beating until light and fluffy, about 1 minute.

Set first layer, top down, on a flat plate. Spread 1 cup of the frosting on top. Top with the second cake layer and spread remaining frosting on the top and sides of the cake, making attractive swirls.

Yield: 12 servings.