Few flavors satisfy this Lebanese girl's sweet tooth quite like chocolate and mint. My Peppermint Chocolate Brownies are a family favorite for the layers of chewy brownie, cool mint buttercream, and perfectly smooth chocolate top layer. Like and Andes Mint, taken all the way to the top level! These are rich, so they are nice cut in small 1-inch bites as well.
Place an oven rack in the center position and heat the oven to 350°F. Grease the bottom only of a 13x9x2-inch baking pan. Set aside.
In a medium saucepan over medium heat, melt the butter and chocolate, stirring occasionally, about 5 minutes. Remove from the heat and whisk in the granulated sugar and espresso powder.
Add the eggs, one at a time, whisking until smooth after each addition. Stir in the flour, salt, and cocoa powder until combined. Pour into the prepared pan and bake until the edges begin to pull away and a toothpick inserted in the middle of the pan yields just a few moist crumbs, about 35 minutes. Cool completely.
Peppermint Buttercream Layer
In a medium bowl or stand mixer fitted with the paddle attachment, beat the butter on medium speed until smooth, about 2 minutes. Add the confectioners sugar and beat very slowly at first to moisten, then on medium until combined. Stop and add 1 tablespoon milk, then beat again to incorporate. Add the peppermint extract and green food coloring and beat again until well-combined.
Spread the buttercream evenly over the cooled brownies. Smooth the top (an an offset spatula makes this easy). Refrigerate.
Chocolate Top Layer
In a small saucepan over medium heat, melt the butter and chocolate chips until melted and smooth, stirring occasionally. Pour over the chilled mint layer and spread evenly (again a clean offset spatula does the job well).
Chill at least one hour and up to 5 days.
To clean cut the brownies, set up a tall glass full of hot water and a paper towel. Use a sharp knife to make one swift cut at a time, dipping the knife in the hot water and wiping clean with the paper towel after each cut.
Store the brownies in the refrigerator to hold their shape. Delicious cold or room temperature.