Directions 13 steps | 65 Minutes
Preheat the oven to 350°F. Grease a 9x13-inch pan with a thin layer of nonstick spray. Line the bottom and sides of the pan with parchment paper. Measure and prep all ingredients.
Make the peppermint brownie batter. In a heatproof microwave-safe bowl, add the unsalted butter and chopped chocolate. Melt in 30-second intervals, stirring in between each interval, in the microwave until smooth. Set aside to cool.
In a separate bowl, whisk together the flour, cocoa powder and salt. Set aside.
In a large mixing bowl, add the granulated sugar, light brown sugar, room temperature eggs and vanilla extract. Vigorously whisk either by hand or electric mixer. Whisk for about 2-3 minutes, or until the mixture lightens in color and turns frothy/bubbly.
Continue mixing as you slowly pour in the cooled chocolate mixture. Whisk until combined.
Sift in the all-purpose flour, cocoa powder and salt. Mix until smooth being careful not to over mix. The batter should be thin, but not watery.
Fold in the crushed peppermint.
Evenly spread the brownie batter in the prepared pan. Bake for 45 minutes until the brownie is puffed in the center with deep cracks throughout the surface. Poke a toothpick into one of the cracks and test for doneness. It should come out with thick and slightly dry streaks of batter.
Allow the brownies to cool inside the pan for about 30 minutes. Then turn them out onto a cooling rack. You may need to run a knife between the parchment paper and the inside of the pan to help release them.
While the peppermint brownies are cooling, make the chocolate peppermint frosting. In a bowl, using an electric hand or a stand mixer with the whisk attachment, beat the unsalted butter until smooth. Add in the cocoa powder.
Add the powdered sugar, one cup at a time. Mix in the peppermint extract and salt. Mix in the heavy cream.
Spread a layer of chocolate peppermint frosting over the top of the cooled brownies.
Garnish with extra crushed peppermint, if desired. Enjoy!