This is a simple recipe that you could also make with cream soda, ginger ale, or cola.
1 yellow cake mix
12 oz root beer
1/4 C vegetable oil
Preheat oven to 350 F. Grease and flour a 10-inch Bundt pan. Mix the cake mix, can of root beer, oil, and eggs and beat well. Pour batter into pan. Bake for 35-40 minutes, until a toothpick inserted comes out clean. Cool cake in pan for 15 minutes, then turn it upside-down on a wire rack. While it is still warm, poke holes in the cake with a skewer. Pour the Root Beer Glaze over the cake.
Root Beer Glaze
1/2 C powdered sugar
3 T root beer
Combine sugar and root beer. Beat until smooth.