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close up shot of slices of Mint Chocolate Brownies on a plate

Mint Chocolate Brownies

Mint chocolate brownies are irresistibly thick and fudgy. This sweet dessert features moist chocolate brownies, mint buttercream, and a rich chocolate ganache.
5 from 2 votes
Prep Time 20 mins
Cook Time 40 mins
Chill Time 1 hr 20 mins
Total Time 2 hrs 20 mins
Course Dessert
Cuisine American
Servings 16


  • 1 box brownie mix, plus ingredients listed on the box to make the brownies (typically eggs, oil, and water)

Mint Buttercream

  • ¾ cup salted butter, softened
  • 2 cups powdered sugar
  • 1 teaspoon mint extract
  • 1 to 2 drops of green food coloring
  • 1 to 2 tablespoons heavy whipping cream


  • 2 cup semi-sweet chocolate chips
  • 1 cup heavy whipping cream


  • Preheat the oven as indicated on the brownie box. Line an 8x8 square baking pan with parchment paper and set it aside.
  • Prepare and bake brownies in an 8x8 square baking dish according to the package instructions.
  • Cool brownies completely.
  • Prepare the buttercream layer by beating the butter until smooth in a mixing bowl. Add the powdered sugar and beat until combined (mixture will be dry).
  • Add mint extract, green food coloring, and 1 tablespoon of heavy cream. Beat until smooth and combined. Taste the frosting and adjust tint or add additional extract if desired. Add an additional tablespoon of heavy cream and beat until fluffy and smooth.
  • Use an offset spatula to spread the mint buttercream in an even layer over the top of the cooled brownies. Place in the refrigerator or freezer to firm the buttercream.
  • Heat the heavy cream in a microwave-safe bowl until steaming (do not boil).
  • Pour hot cream over the chocolate chips. Let sit for 3 to 4 minutes with a plate over the bowl to allow the chocolate chips to soften in the hot cream.
  • Whisk the chocolate until a smooth ganache forms.
  • Spread ganache over the chilled, frosted brownies.
  • Allow the ganache to set (either on the countertop for 45 to 60 minutes or in the refrigerator for about 15 minutes).
  • Lift brownies from the tray by the flaps of parchment paper. Cut into even squares and serve.


  • Mint extract and peppermint extract have different flavors. We like this combo with mint extract, but peppermint extract would also be yummy.
  • The frosting is light and fluffy - chilling it before adding the ganache will help it hold up to the addition of the warm ganache. I popped the frosted brownies in the freezer for about 20 minutes before adding the ganache.
  • If you try to cut your brownies before they are cooled enough, you won’t get clean cuts. Try to resist sampling until they are cool.