Dark chocolate and peppermint are great friends. Perhaps the most famous product with this combination is the York Peppermint Pattie, another amazing confection pioneered right here in the Commonwealth of Pennsylvania in the 1940s.
This cake tastes much like a York Peppermint Pattie, even though the candies aren’t used in the recipe. Next time, instead of crushing red and white mints for the cake’s garnish, I’d like to cut Peppermint Patties into halves or quarters and place them along the edge of the cake for the border. One other item to note about this recipe: the original recipe that I found online called for 3/4 cup of boiling water to be stirred in by hand once all of the other ingredients were blended. This seemed like far too much liquid to me, so I used 1/2 cup…which in hindsight was still too much liquid. Although the cake turned out well, the center fell significantly during cooling, so next time I’ll use no more than 1/4 cup.
For the dark chocolate sheet cake:
- 2 cups sugar
- 1 3/4 cups flour
- 3/4 cup Dutch process cocoa
- 1 1/2 teaspoons baking powder
- 1 1/2 teaspoons baking soda
- 1 teaspoon salt
- 2 eggs
- 1 cup milk
- 1/2 cup vegetable oil
- 2 teaspoons vanilla extract
- 1/4 cup boiling water
For the peppermint vanilla buttercream frosting:
- 8 tablespoons butter, softened
- 2 1/2 cups powdered sugar, sifted
- 2 teaspoons peppermint extract
- 1/2 teaspoon vanilla extract
- 2 tablespoons heavy cream
- red and white peppermint candies, crushed (optional)
Preheat oven to 350 degrees. Spray a 9 x 13 pan with baking spray.
Place sugar, flour, cocoa, baking powder, baking soda, and salt in a mixing bowl and stir to combine. Add eggs, milk, vegetable oil, and vanilla and beat on medium speed for 2 minutes, until very well combined.
Gently stir in boiling water by hand; batter will be thin. Pour into prepared pan and bake for 35-40 minutes, until a cake tester inserted in the center comes out clean. Cool completely in pan before frosting.
To prepare the frosting, place butter in a mixing bowl and beat on medium speed for 1 minute using a paddle attachment. Add powdered sugar and beat on low speed until the sugar is fully incorporated; this will take several minutes. I cover my mixer with a kitchen towel to prevent a powdered sugar storm.
Scrape the sides of the bowl and add peppermint extract, vanilla extract, and 1 tablespoon heavy cream. Beat until well combined, scraping sides of the bowl frequently; beat in additional tablespoon of heavy cream and continue beating for 1-2 minutes for a smooth, even consistency.
Frost the cake and sprinkle the edges with crushed peppermint candies if desired.