Watergate Cake is one of those recipes where no one’s really sure of the exact origin of the cake and conflicting stories are abound. Some claim the cake was based on Watergate salad, while others claim the salad was based on the cake. Neither were invented at the Watergate Hotel, the location known for the burglary that eventually led President Richard Nixon to resign. But whatever the origins, the cake itself has been around since the mid 1970s and pleasing pistachio fans for decades since.
The cake uses boxed cake mix combined with instant pistachio pudding mix and extra pistachio nuts thrown in for good measure. The frosting is a whipped version that also contains pistachio pudding mix. If you or anyone you know likes pistachios, make this cake as soon as you can.
Watergate Cake Ingredients
- Boxed yellow cake mix: This recipe is off to an easy start with boxed cake mix. Yellow cake, while tasty, can be kind of a blank slate, and that makes it the perfect base for adding pistachio flavor.
- Instant pistachio pudding mix: Powdered instant pudding mix provides the pistachio flavor in the cake.
- Club soda: Boxed cake mixes typically call for water or milk, but for this recipe, you’ll add club soda. The carbonation helps make the batter fluffier, producing a lighter texture in the cake.
- Eggs: The boxed cake mix likely requires adding large eggs because they’ll bind all the ingredients together.
- Pistachios: Add shelled pistachios to the batter for extra crunch and flavor.
- Instant pistachio pudding mix: Adding instant pistachio pudding powder to the frosting is the best way to make the pistachio flavor of the cake even more intense.
- Heavy whipping cream: This lets you create a whipped frosting that will be easier to spread than plain pudding, which would be too liquidy.
- 2% milk: You’ll need this to make the pudding portion of the frosting.
Directions
Step 1: Make the cake layer
Preheat the oven to 350°F and grease a 13×9-inch baking pan. Combine the cake mix, pudding mix, club soda, canola oil and the eggs in a large bowl. With an electric mixer, beat the mixture on low for 30 seconds and on medium for two minutes. Mix in the pistachios. Pour the batter into the greased baking pan and bake for 30 to 35 minutes. The cake is done when a toothpick inserted in the center comes out clean. Cool the cake on a wire rack.
Step 2: Make the frosting and add it to the cake
Stir together the pudding mix, whipping cream and milk in a small bowl. Beat the mixture until it forms soft peaks; it should be spreadable at this point. Spread the frosting over the cake.
Watergate Cake Variations
- Try using a white cake mix: If you have boxed white cake mix, go ahead and try it. You’re flavoring it with pistachio pudding mix anyway, so the resulting flavor may not be very different. Just be aware that the color of the cake could turn out to be more green, as there’s no yellow color in the cake to compete with the green color of the pudding.
- Add some chopped pistachios on top of the frosted cake: If you really want to push that pistachio flavor, sprinkle some chopped pistachios around and on the cake after frosting it.
How to Store Watergate Cake
This cake has a whipped cream frosting so it must be stored in the refrigerator. The whipped cream frosting won’t harden in the cold environment of the refrigerator so wrapping the cake in plastic wrap isn’t a good idea. Instead, follow this hack using a flipped food storage container for individual slices.
How long does Watergate Cake last?
The cake layer can last several days in the refrigerator, but the quality of the frosting may start to decline before then. It’s best to use up leftover Watergate Cake within three days.
Watergate Cake Tips
Can you use seltzer or tonic water instead of club soda?
Don’t use tonic water. It’s flavored with quinine and has a bitter taste that will affect the flavor of the cake. As for seltzer, that actually has fewer minerals than club soda, which again, can affect the taste of the cake. However, the differences between club soda and seltzer are small enough that you could use seltzer in a pinch. Just don’t use flavored seltzer. By the way, you could also use mineral water or sparkling water if you were unable to find club soda.
Can you use plain water instead of the club soda?
Technically you could use plain water if the boxed cake mix normally requires it. However, the lack of carbonation may result in the cake being less fluffy and light. Using carbonated water in dough or breading is actually very common (it’s a great way to make waffles lighter, too), and if you can get your hands on club soda or mineral, sparkling or seltzer water, those are preferable to plain water in this recipe.
Can you make this into a layer cake?
Yes, but keep two things in mind: you’ll need to find two pans that, when combined, have the same amount of space for the cake mix. For a 13×9-inch pan, try dividing the batter between two 9×2-inch round cake pans. The layers may end up being a bit thinner than the one layer from the 13×9-inch pan. Bake it at the same temperature but start checking the cake a bit early. The other issue is filling. You can use a little of the frosting in between layers or maybe a thin layer of plain whipped cream. Check out these other tips on how to frost a layer cake for great results.
