Root Beer Cake

2 cups root beer 1 cup dark unsweetened cocoa powder 1/2 cup unsalted butter , cut into 1-inch pieces 1 1/4 cups granulated sugar 1/2 cup dark brown sugar ,[...]

1 (18 ounce) box white cake mix (Betty Crocker Supermoist preferred) 1 (12 ounce) can root beer (1 1/2 cups) 1/4 cup vegetable oil 3 egg whites 1 teaspoon[...]

1 1/4 cups all-purpose flour 3/4 cup sugar 1/3 cup butter or 1/3 cup margarine , softened 3/4 cup root beer 3/4 teaspoon baking powder 1/2 teaspoon salt 1/4[...]

1 (18 ounce) package Betty Crocker super moist white cake mix 1 1/4 cups water 1/3 cup vegetable oil 3 egg whites 1/2 teaspoon ground allspice 1/2 teaspoon[...]