root beer (substitute for the water the box calls for)
Root Beer Float Frosting:
1/3 cup butter, softened
3 cups powdered sugar
3 tablespoons root beer
1 tablespoon vanilla
Preheat your oven to 350-degrees. Grease and flour two round cake pans and, set aside. Prepare the cake mix according to the package (I like Duncan Hines Classic Chocolate), substituting root beer for the water. Then add the vanilla, and beat. Pour the batter into the pans and cook as per the directions on the box. Let the cake cool completely.
While the cake cools, mix up the frosting. Beat the softened butter until smooth and add in 1 cup of powdered sugar, gradually. Beat this really well until nice and smooth. Add the vanilla and the remaining powdered sugar and continue beating until smooth. You can add more root beer or more powdered sugar to get a thicker or thinner consistency as desired.
Frost the cake and refrigerate for 1 hour before cutting… I use a bit of wax paper under the edges of the cake so I don’t get frosting on my platter.
Store in the fridge, covered.
Tip: this root beer cake is even better the second day, if it lasts that long!