Watergate Cake IV By Anonymous recipe Comments | 0 Favorites | 7 Print Pistachio cake with fluffy pistachio frosting. Watergate Cake IV Ingredients 1 (18.25 ounce) package white cake mix3 eggs1 cup vegetable oil1 cup lemon-lime flavored carbonated beverage2 (3 ounce) packages instant pistachio pudding mix1 cup frozen whipped topping, thawed1 cup cold milk Instructions 1 Combine cake mix, eggs, oil, soda drink and 1 box pistachio pudding. Pour batter into a greased and floured 13 x 9 inch pan. 2 Bake at 350 degrees F (175 degrees C) for 30 to 40 minutes, or until a toothpick inserted into cake comes out clean. Cool completely. 3 While cake is baking, mix 1 box pistachio pudding, whipped topping, and milk. Chill. Ice cooled cake with chilled frosting.