Watergate Cake is a moist, fluffy pistachio flavored cake with pineapple and marshmallows. It's inspired by classic Watergate Salad. It's the perfect cake for a Spring or Summer event!
Mix all of the ingredients together until blended. Pour into two prepared 9" cake pans.
Bake at 350 degrees for 25-35 minutes or until center comes out done. Remove and cool completely on a wire cake rack.
To Assemble Cake:
Once the cakes are cool, start with one cake layer and spread about 3/4 cup of prepared Watergate salad on top of that cake round.
SPECIAL NOTE: If your watergate salad is runny at all and not thick, add more mini marshmallows before spooning onto the cake. The marshmallows help to absorb the liquid and thicken it up a little more.
Gently place the other cake on top of the Watergate Salad sandwiching it between the two layers. Press down gently.
Use a spatula to remove any access watergate salad that is pressed out around the sides.
To Make Frosting:
Whisk milk and instant pudding about 2 minutes. Gently fold in the whipped cream. Spoon and spread evenly on cooled cake.
Top the cake with about 1/4 cup of watergate salad, if desired. Sprinkle chopped walnuts on top.
Refrigerate cake at least 1 hour before serving. Serve chilled.