Preheat oven to 350°. Grease and flour a 9 x 13 inch baking pan.

Combine the cake ingredients in a mixing bowl. Beat mixture at low speed with an electric mixer until dry ingredients are moistened. Pour batter into the prepared 9 x 13 pan pan.

Bake at 350° for 30 minutes or until a wooden pick inserted in center comes out clean. Cool cake 10 minutes. Spread Root Beer Frosting evenly over warm cake (would pour it over a cooled cake).

For the frosting, bring first 3 ingredients to a boil in a large saucepan over medium heat, stirring until butter melts. Remove from heat; whisk in powdered sugar and vanilla until smooth. Serves 15.