Watergate Cake

Watergate Cake is an easy, mix-and-stir dessert that vanishes off the pan in no time. You start with a simple cake mix, stir in pistachio pudding and ginger ale, and it bakes up soft, moist, and gently sweet. Top it with a fluffy pistachio whipped frosting that tastes like pudding and whipped cream all in one, and you get a pretty pale green cake that’s perfect for St. Patrick’s Day, spring potlucks, or anytime you want a fun dessert that doesn’t weigh you down.

Mama and I baked this at my house the other day so we could photograph it, and the whole pan was gone before the day was over. The grandkids kept sneaking back for “just one more little piece” until there was nothing left but crumbs. It has that gentle pistachio flavor, soft cake, and cloud-like frosting that keeps everyone coming back with a fork in hand.

Before You Get Started

• Use white cake mix for color: A white cake mix will give you the prettiest green color from the pistachio pudding. Yellow cake mix also works but the color will be deeper.
• Room temperature ingredients help: Let your eggs sit out for a bit and make sure the ginger ale is not ice cold. This helps the batter mix smoothly.
• Use instant pistachio pudding: You need instant, not cook-and-serve, so it thickens correctly in both the cake and the frosting.
• Chill the frosting a bit: The pistachio whipped topping thickens as it chills, so plan to refrigerate the cake after frosting for the best texture.
• Make it ahead for parties: This cake keeps well in the fridge, so it is a great make-ahead dessert for St. Patrick’s Day or any holiday.

Ingredients

• White cake mix
• Instant pistachio pudding mix
• Vegetable oil
• Eggs
• Ginger ale or 7UP
• Cold milk
• Whipped topping
• Nuts (optional)

How To Make Watergate Cake

1. Mix the cake batter

In a medium or large mixing bowl, combine the cake mix, 1 box of pistachio pudding mix, vegetable oil, eggs, and ginger ale or 7UP. Beat with an electric mixer until the batter is smooth and well combined.

2. Bake the cake

Pour the batter into a greased 9 x 13 inch baking pan. Bake at 350 degrees for 30 to 35 minutes, or until a toothpick inserted into the center of the cake comes out clean. Set the cake aside to cool completely in the pan.

3. Make the pistachio frosting

In a medium bowl, add the cold milk to the remaining box of instant pistachio pudding mix. Stir or beat with an electric mixer until well combined and the pudding begins to thicken. Gently fold in the whipped topping until the mixture is light, fluffy, and evenly blended.

4. Frost and garnish

Spread the pistachio frosting over the completely cooled cake. Sprinkle chopped nuts over the top if you like for a little crunch and extra flavor.

5. Chill and serve

Refrigerate the Watergate Cake until chilled, then slice and serve. Keep any leftovers stored in the refrigerator.

Fun Ideas For St. Patrick’s Day

• Lean into the green: Because this pistachio cake is naturally green, it makes such a fun St. Patrick’s Day dessert. Add a few extra green sprinkles or maraschino cherries on top if you want it even more festive.
• Make it a green food day: Over the years, Mama always tried to squeeze in as much green food as she could for St. Patrick’s Day. Light-colored foods take food coloring best, so think about things like mashed potatoes, rolls, or drinks if you want to add a green tint.
• Have a little fun with the kids: I’ve been known to put a few drops of green food coloring in every toilet in the house so the kids wake up and check to see if the “leprechauns” visited. It is silly, but the kids remember it long after the cake crumbs are gone!

Storage

Store Watergate Cake in the refrigerator, tightly covered, for up to 5 to 6 days.

You can also bake the cake layer ahead of time, cool it completely, wrap it well, and freeze it (unfrosted) for up to 3 months. Thaw at room temperature before adding the pistachio whipped topping.

Recipe Notes

• About smaller cake mix boxes: Cake mix box sizes have gotten a bit smaller over the years, but there is no need to adjust the recipe. Use the standard box and proceed as directed.
• Cake mix swaps: In a pinch, you can use a yellow cake mix. The flavor will still be good, but the green color will be a little deeper than with white cake mix.
• Soda options: We used ginger ale because that is what we had on hand. You can also use Sprite, 7UP, club soda, or any clear soft drink in this recipe.
• Extra mix-ins: For added flavor and texture, stir in 1/2 cup each of chopped pecans and sweetened shredded coconut flakes into the cake batter.
• Whipped topping choices: Cool Whip, Dream Whip, or homemade whipped cream all work well in the frosting. Just make sure it is fully whipped before folding into the pudding.
• Garnish ideas: Top your cake with maraschino cherries for a pop of color, chopped pecans for crunch, or extra pistachios if you want to really lean into the pistachio flavor. This makes it a pretty dessert for both St. Patrick’s Day and Christmas.