1 (18 1/4 oz.) pkg. white cake mix
1 3/4 c. cold root beer, divided
1/4 c. vegetable oil
2 eggs
1 envelope whipped topping mix

Preheat oven to 350°F. In a mixing bowl, combine cake mix, 1 1/4 cups root beer, oil and eggs. Beat on low speed for 2 minutes or by hand for 3 minutes. Pour into a greased 9 x 13-inch baking pan.

Bake at 350°F for 30 to 35 minutes or until toothpick inserted in center comes out clean. Cool completely on wire rack. In a mixing bowl, combine whipped topping and remaining root beer. Beat until soft peaks form. Frost cake. Store in refrigerator.