Serve this moist cake to a bunch of hungry kids and watch it disappear.
In a mixing bowl, combine dry cake mix, 1 1/4 cups root beer, oil and eggs. Beat on low speed for 2 minutes or stir by hand for 3 minutes.
Pour into a greased 13 x 9 x 2-inch baking pan. Bake at 350° for 30-35 minutes or until a toothpick inserted near the center comes out clean. Cool completely on a wire rack.
In a mixing bowl, combine the whipped topping mix and remaing root beer. Beat until soft peaks form. Frost cake. Store in the refrigerator. Yield:12-16 servings.