Ingredients:
 
2 cups all-purpose flour, sifted
1 teaspoon baking soda
2 cups granulated sugar
1 cup (2 sticks) unsalted butter
1 1/2 cups miniature marshmallows
3 tablespoons unsweetened cocoa powder
1 cup Dr. Pepper
2 eggs
1 1/2 cups buttermilk
1 teaspoon vanilla extract

DR. PEPPER FROSTING

1/2 cup (1 stick) unsalted butter, softened
6 tablespoons Dr. Pepper
3 tablespoons unsweetened cocoa powder
1 (1 pound) box confectioners’ sugar, sifted
1 teaspoon vanilla extract
1 cup chopped pecans
 
Directions:

Preheat the oven to 350 degrees F. Grease, but do not flour, a 9 by 13-inch pan. Set it aside.

In a large bowl, sift together the flour and baking soda. Gradually stir in the sugar. Set aside.

In a saucepan, heat the butter, marshmallows, cocoa, and Dr Pepper. Stir constantly until the butter and the marshmallows are melted. Do not allow the mixture to boil. Pour the marshmallow mixture over the flour mixture. Beat well. Set aside.

In another bowl, beat the eggs until they are light and fluffy. Stir in the buttermilk and vanilla extract. Mix well. Beat the egg mixture into the flour mixture until well blended and the batter is smooth. Pour the batter into the prepared pan.

Bake for 50 to 55 minutes, or until the center of cake springs back when lightly touched. Let the cake cool on a rack for 10 minutes.

Spread Dr. Pepper Frosting over the warm cake.

DR. PEPPER FROSTING

In a saucepan, combine the butter, Dr Pepper, and cocoa powder. Bring the mixture to a boil over low heat, stirring constantly. Remove the pan from the heat. Gradually stir in the confectioners’ sugar until the mixture is smooth, then fold in the vanilla extract and the pecans.