My favorite fudgy brownies with a soft mint layer and ganache is the definition of decadence. Fresh mint elevates the mint chocolate combo to a whole new level!

Mint Chocolate Brownie squares stacked on top of each other

OVERVIEW

If you’ve ever had a Thin Mint Girl Scout cookie then you know how delicious the chocolate and mint combo can be! These brownies are even more incredible and their festive green color make them perfect for St. Patrick’s Day.

They start with my favorite cocoa powder brownies then get topped with a layer of mint buttercream frosting. I infused fresh mint leaves into the butter for the buttercream! That’s what really sets these brownies apart as most recipes call for a mint extract to be used. Fresh mint helps to avoid that ultra sweet toothpaste flavor.

Next up, the brownies are topped with a layer of silky dark chocolate ganache. These are truly worthy of a celebration and can’t be matched!

Mint Chocolate Brownies stacked up

What is a grasshopper brownie?

Mint chocolate brownies are also known as Grasshopper Brownies or Crème de Menthe Brownies. All of these essentially mean the same thing = chocolate and mint.

Grasshopper Brownies get their name from a cocktail. The Grasshopper Cocktail is an early 1900’s cocktail made with crème de menthe and crème de cacao. While these brownies don’t contain alcohol they do share the same flavors as the traditional cocktail. 

How to Infuse Herbs into Butter

For this recipe, I really wanted to use fresh mint. I wanted to include this in the buttercream layer so I could color it green. To do so I needed to infuse the mint leaves into the butter. This method works great for any herb you’d like to infuse!

You could infuse herbs like rosemary, thyme, or sage into butter and use a meat rub, spread over grilled vegetables, or spread onto bread.

You can also use this mint infused butter in a cookie recipe!

Here’s my method

Step 1: Melt Butter in a sauce pan over medium-low heat.

Step 2: Roll fresh herbs into the palm of your hand. You want to crunch them up a bit so that the flavors can be easily extracted.

Step 3: Add the herbs to the melted butter and stir until fully submerged. Turn up the heat to medium-high and boil for 1 minute.

Step 4: Turn off the heat, cover the pot, and let it steep. The longer it steeps the more flavor will be extracted. I recommend at least 30 minutes.

Step 5: For this recipe, I strained out the herbs and re-solidified the butter. Alternatively, if you are using this as a spread or rub, you can leave the whole herb leaves in the butter and either use melted or re-solidified.

Mint Chocolate Brownies stacked up

STORAGE

Brownies keep well at room temperature in an airtight container for up to 4 days. If you would like to freeze the brownies, slice them and wrap them well in plastic wrap. Frozen brownies will keep up to 3 months in the refrigerator.

MORE RECIPES FROM BAKER BETTIE!

If you loved this mint brownie recipe, you might like to try these other brownie recipes!

Here are some other festive, holiday favorites perfect for a St. Patrick’s Day celebration.

Mint Chocolate Brownie squares stacked on top of each other
Yield: 9 Large Brownies

Mint Chocolate Brownies

Prep Time 2 hours 10 minutes
Cook Time 33 minutes
Total Time 2 hours 43 minutes

My favorite fudgy brownies with a soft mint layer and ganache is the definition of decadence. Fresh mint elevates the mint chocolate combo to a whole new level!

Ingredients

For the Brownies

  • 113 grams (½ cup, 1 stick) unsalted butter, melted and hot
  • 100 grams (½ cup) granulated sugar
  • 150 grams (¾ cup) brown sugar, preferably dark brown sugar
  • 53 grams (⅔ cup) natural cocoa powder
  • 2 large eggs, room temperature
  • 2 teaspoons vanilla extract
  • ½ teaspoon kosher salt
  • ⅛ teaspoon baking soda
  • 85 grams (½ cup + 3 tablespoons) all-purpose flour

For the Buttercream

  • 227 grams (1 cup, 2 sticks) unsalted butter
  • 14 grams (0.5 ounce package) fresh mint *see note below
  • 300 grams (2 ½ cups) powdered, icing, or confectioners sugar
  • ¼ teaspoon kosher salt
  • 28-42 grams (2-3 tablespoons) milk or heavy cream
  • 1-2 drops green food coloring, gel or liquid is fine

For the Ganache

  • 113 grams (4 ounces) bittersweet or semi-sweet chocolate
  • 118 grams (½ cup) heavy cream, whipping cream, or double cream
  • pinch of salt

Instructions

Prep: 

  1. At least 30 minutes before baking, take the eggs (2 large) out of the refrigerator to come to room temperature. Measure out the rest of the ingredients.
  2. Position an oven rack in the center position. Preheat the oven to 325°F/165°C. 
  3. Line an 8-inch (20 cm) square pan with parchment paper leaving overhang on all sides. How to Perfectly Line a Square Pan with Parchment.


Make Infused Butter for the Buttercream:

  1. Melt the butter (227 grams, 1 cup) in a saucepan over medium heat.
  2. Roughen up the fresh mint leaves (14 grams, 0.5 ounce package) by rolling them around in your hand. You want to break them up a bit so that the flavor can easily escape. Add them to the saucepan and stir until the leaves are fully covered. Turn up the heat to medium-high for 1 minute.
  3. Turn off the heat, cover the pot, and set it aside to steep. The longer it steeps the more flavor will extract. Steep for a minimum of 30 minutes.
  4. After steeping, strain out the mint leaves. Cool the butter completely until it solidifies but still stays soft. You can speed this up by placing the butter in the fridge.

While the infused butter is solidifying, Make the Brownies: 

  1. Melt the butter (113 grams, ½ cup) either in the microwave or in a saucepan on the stove. The butter needs to be very hot! 
  2. In a large mixing bowl, whisk together the granulated sugar (100 grams, ½ cup), brown sugar (150 grams, ¾ cup), and cocoa powder (53 grams, ⅔ cup). Add the hot melted butter and whisk to combine. 
  3. Add the vanilla extract (2 teaspoons) and the eggs (2 large), whisking vigorously for about 30 seconds. 
  4. Add the salt (½ teaspoon), baking soda (⅛ teaspoon), and flour (85 grams, ½ cup + 3 tablespoons) to the bowl and stir with a mixing spoon or silicone spatula for about 30 seconds to help develop the gluten/chewiness. 
  5. Transfer the brownie batter into your prepared pan and spread evenly.
  6. Bake at 325°F/165°C for 28-33 minutes until a toothpick inserted in the center comes out with moist crumbs clinging to it. 
  7. Set the pan on a cooling rack to cool completely.

While the brownies cool, make the buttercream:

  1. In the bowl of a stand mixer fitted with a paddle attachment, or in a large bowl with a hand mixer, beat the softened infused butter on medium speed for about 1 minute, until fluffy. Scrape down the sides and bottom of the bowl.
  2. Add the powdered sugar (300 grams, 2 ½ cups) into the mixing bowl and start mixing on low until the sugar starts to combine with the butter. Turn the mixing speed up to medium-high and beat for about 3 minutes until the mixture is light and fluffy. Mix in the salt (¼ teaspoon).
  3. Add a bit of milk or heavy cream (28-42 grams, 2-3 tablespoons) if needed to thin out the texture. If the texture becomes too thin, you can add a bit more powdered sugar until you get a spreadable consistency. 
  4. Add green food coloring one drop at a time until you get a soft mint color. I used one drop of gel food coloring.
  5. Top the buttercream over the completely cooled brownies. Spread the buttercream evenly using a spatula. Move the pan to the fridge for at least 30 minutes.

Make the ganache:

  1. Chop the chocolate (113 grams, 4 ounces) up into small pieces and place in a large mixing bowl. Alternatively you can use chocolate chips. 
  2. Heat the cream (118 grams, ½ cup) in a saucepan over medium heat until it is simmering. 
  3. Pour the hot cream over the chocolate and let stand for 5 minutes. Add the salt (one pinch).
  4. Put the whisk directly in the center of the chocolate/cream mixture and begin whisking in small circles and slowly moving outward in bigger circles until the mixture is smooth. 
  5. Let ganache cool to room temperature. It will thicken as it cools.
  6. Once cooled, spread the ganache ovenly over the frosted brownies using a spatula. Return to the fridge for at least 30 minutes.
  7. Using the parchment overhang, carefully remove the brownies from the pan. Cut into squares and serve.

Notes

*Instead of fresh mint, use 1 teaspoon pure mint or peppermint extract.

Storage: Mint Chocolate Brownies can be stored in an airtight container in the refrigerator for up to 1 week.

TIP: To get a clean edge on your brownies, trim off a very thin layer on all edges. Wipe your knife clean between every cut.

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