- Preheat oven to 350 F.
- Grease and flour two 9" round pans.
- Mix cake mix, 3/4 cup root beer, eggs, oil and pudding mix in a large bowl.
- Bake as directed on package.
- Chill cake for ease in splitting layers.
- Split each layer into 2 thin layers.
- Filling and Topping: Combine Dream Whip, ice cold root beer and vanilla in a chilled bowl.
- Beat as directed on package. Spread 1 cup of filling between layers of cake with remaining on top.
- Serve immediately or store in refrigerator until ready to serve.