The thick mint layer is the whole point of mint chocolate brownies, and it’s the part most recipes shortchange. If you’ve made a pan before and the green layer came out as a thin stripe that looked nothing like the photos, the problem wasn’t how you spread it. The recipe didn’t give you enough buttercream for the size of the pan.

Here you spread a full batch of mint buttercream over a small pan of fudgy brownies, then pour chocolate ganache over the top: dark brownie on the bottom, a thick band of mint green through the middle, and a glossy chocolate top.

A close-up of a Mint Chocolate Brownie with a bite taken out, showing layers of chocolate ganache, mint cream, and brownie, served on a white plate with a fork and a bowl of chocolate chips—perfect for any Mint Chocolate Brownies Recipe.

These are the squares that disappear first from a St. Patrick’s Day tray, and they earn the same spot on a Christmas platter. I kept a boxed brownie mix as the base on purpose: you’re already making two layers from scratch, and the mix is the one shortcut nobody minds.

Getting the Mint Layer Right

The buttercream will look like too much while you spread it. It isn’t. That thickness is the whole middle layer, so use all of it.

A square pan of Mint Chocolate Brownies sits on a marble surface, topped with a large mound of light green frosting in the center, ready to be spread. The pan is lined with parchment paper.

Buy mint extract, not peppermint extract, because the two make different desserts. Mint gives these the flavor of mint chip ice cream. Peppermint pushes the same pan toward candy canes.

Extract strength varies from brand to brand, so add it, beat it in, and taste the buttercream before you spread it. You want mint chip ice cream, not toothpaste, and if you can barely taste the mint, beat in a few more drops.

If it’s the candy cane version you want, my peppermint brownie recipe is what you’re looking for.

Go slowly with the green food coloring and judge by the color, not the drop count. Brands vary more than you’d think.

A square metal baking pan lined with parchment paper holds a smooth layer of light green batter, perfect for a Mint Chocolate Brownies Recipe, set on a white marble surface.

When my recipe tester, Teresia, made this recipe, she needed six drops of grocery store coloring. I needed half that with a different brand. Stop at pale mint green.

Why the Ganache Is Worth the Wait

The glossy poured top is real chocolate ganache, and a ganache layer this thick usually needs several hours in the refrigerator before it will cut cleanly. Not this one. It only needs two hours to firm up.

A square Mint Chocolate Brownie with layers of brownie, green mint filling, and smooth chocolate topping sits on parchment paper on a wooden board. A glass of milk and a bowl of chocolate chips complete this tempting Mint Chocolate Brownies recipe.

It’s the same ganache I pour over my Baileys cheesecake and my Skrewball pie, and it behaves the same way here.

You don’t have to trust the clock, because the ganache shows you when it’s ready:

It sets from the edges of the pan inward, so if it’s soft or it’s wet-looking in the cent, it means the ganache needs more time.
When the center looks the same as the ganache near the edges of the pan, it’s set. Tilt the pan under the light and the difference shows up.

Cutting Squares That Look Like the Picture

A knife smears these brownies because it passes through three layers with three different textures, and it drags the soft layers through the firm ones.

Chill the pan until the ganache is fully set. If the brownies have been in the refrigerator for hours, let the pan sit on the counter for a few minutes first, so the brownie base softens enough that the blade doesn’t crack the chocolate top.

A knife slices into a square dessert with a chocolate top layer and a green mint layer, set on a wooden cutting board. These Mint Chocolate Brownies are cut into nine squares, with a white napkin nearby.

Then cut with a sharp knife and wipe the blade clean between cuts. The wiping is the step people skip, and it’s the difference between a green band with crisp edges and a green smear dragged down into the chocolate.

Nine Mint Chocolate Brownies with a green mint layer are arranged on parchment paper atop a wooden board, surrounded by a knife, chocolate chips, and glasses of milk on a marble surface.

What Testing Changed About This Recipe

I first got this recipe from a friend of mine, and for a long time I made it exactly the way she gave it to me. Teresia tested that original version on March 4, 2026, and her results made me want to go back and change it.

The flavor was good, but the old instructions promised the ganache would set in 15 minutes, and it was still soft after an hour. The brownie layer also tasted more like cake than a fudge brownie.

Both findings sent the recipe back into my kitchen. I swapped the base for a brownie mix with the fudge packet included, and that batch stayed fudgy even after hours in the refrigerator. Then I fixed the ganache so it sets fully within two hours.

This post was originally published in November 2021. The recipe was updated and new photos were taken in July 2026.

Making Them the Night Before

Bake and layer them the day before, let the pan chill overnight, and slice the squares the day you serve them. I’ve left a plate sitting out past the hour mark to see what would happen: the squares soften a little but keep their layers.

A close-up of Mint Chocolate Brownies with layers of dark chocolate, green mint cream, and brownie base—one with a bite taken out—stacked on a wooden surface next to milk and a bowl of chocolate chips. Try this Mint Chocolate Brownies Recipe!.

If you’re carrying them to a party, bring the whole pan, lift the slab out by the parchment when you get there, and cut the squares then. They’ll look better than anything that rode over pre-cut.

If you’re filling out a St. Patrick’s Day tray, my Baileys brownies and mini mint cheesecakes chill on the same overnight schedule.
These have a second season in December, and the mint chocolate doesn’t stop at the brownie pan: my mint chocolate chip cookies and mint chocolate fudge fill out the same cookie tray in cookie and candy form.

Mint Brownies

5 from 8 votes

Mint chocolate lovers will love the combination of fudgy chocolate brownies, fluffy mint buttercream, and a sweet chocolate layer on top of these decadent mint brownies.

Prep Time 20

Cook Time 35

Total Time 3 15

Servings

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Ingredients

Brownie

16 ounce box brownie mix with the fudge packet included plus the ingredients called for on the back of the box for fudgy brownies (Betty Crocker Delights Original Supreme used – 1 large egg, ⅓ cup oil and 3 tablespoons water)

Mint Buttercream

¾ cup unsalted butter room temperature
2 cups powdered sugar sifted
2 tablespoons heavy cream
1 teaspoon mint extract
3-4 drops green food coloring McCormick brand used

Chocolate Ganache

2 cups semi-sweet chocolate chips Ghirardelli brand used
⅔ cup heavy cream
2 tablespoons light corn syrup

Instructions

Brownie

Preheat the oven to 350°F. Line an 8×8 baking pan with parchment paper being sure to leave enough to overhang the sides of the pan. This will make lifting the chilled brownies out of the pan easier.
Prepare the boxed brownie mix according to package directions for fudgy brownies. Bake according to the box directions (our brownies baked for 35 minutes). The edges should be set and the top crackly. A toothpick inserted into the center should come out with a few moist crumbs but no wet batter.
Allow the brownies to cool completely in the pan before adding the mint buttercream layer.

Mint Buttercream

In a large mixing bowl using a handheld electric mixer on medium-high speed, beat the butter for 1-2 minutes or until light and fluffy.
Add the powdered sugar and mix on low just until fully incorporated. The mixture will be dry and resemble coarse crumbs.
To the bowl add the heavy cream, mint extract, and green food coloring. Beat for 1-2 minutes or until fluffy and a uniform light mint green color.
Top the cooled brownie with the mint buttercream and spread to an even layer.
Place the pan into the freezer for 20 minutes to allow the buttercream layer to chill until firm to the touch and no longer soft or sticky before adding the chocolate ganache. This will help to ensure that the warm ganache does not melt the buttercream when added.

Chocolate Ganache

To a microwave-safe bowl, add the semi-sweet chips and heavy cream. Heat for 1 minute. Remove the bowl from the microwave and allow the chips to sit in the hot cream for an additional 1 minute. Stir until smooth. Heat for an additional 30 seconds if needed to fully melt all the chocolate chips.
Add the corn syrup and gently stir until fully incorporated and the ganache is smooth and glossy.
Allow the chocolate ganache to cool on the counter for 5-6 minutes or until cool to the touch and thickened slightly before spooning over the chilled mint buttercream layer.
Remove the brownies from the freezer, gently pour the cooled ganache over the top of the buttercream layer and smooth into an even layer.
Chill the mint chocolate brownies in the refrigerator for 2 hours or until the ganache has fully set before slicing and serving. Use a sharp knife wiped clean between cuts for the cleanest layers. Slice into 16 small or 9 large pieces.

Notes

Do not use a boxed brownie mix with chocolate chips in the batter. The chips get very hard when chilled and will make it tougher to slice when ready to serve.
Betty Crocker Delights Original Supreme (with the syrup pack included) was used for this recipe. It calls for baking at 350°F for 35-38 minutes in an 8×8 pan. If using a different brand than the Betty Crocker, be sure to follow the baking instructions on your box for temperature and time. You may want to note that mixes that are made to be baked in a 9×13 pan, may yield different results.
The chocolate ganache layer needs at least 1 ½ to 2 hours to fully chill and set in the refrigerator for clean slices. However, you can refrigerate the brownies for up to overnight if desired. You may want to allow them to rest at room temperature for 10-15 minutes to allow the brownie layer to soften slightly for easier slicing.
Use pure mint extract, not peppermint extract, for these brownies. Peppermint extract will give a flavor profile more like a candy cane if used.