I want chocolate, and I want mint — and I want it now. These brownies answer that craving with a fudgy base, crunchy Mint Oreos folded inside, and a silky espresso cocoa buttercream on top. They look impressive, but they come together with straightforward steps and a forgiving timeline.

Use a reliable Fudge Brownies Recipe as your base, then add Mint Oreos in two ways: pieces folded into the batter for pockets of minty cookie, and whole cookies arranged on top for texture and visual flair. The espresso buttercream is quick to whisk up while the brownies bake and brings a subtle coffee lift that keeps the chocolate bright.

This post walks through the exact ingredient list and the step-by-step directions I follow every time. I’ll also share equipment you’ll want at the ready, likely pitfalls and how to avoid them, smart substitutions, and storage tips so your brownies stay indulgent for days.

Ingredients at a Glance

1 Fudge Brownies Recipe — the base; follow your trusted fudgy brownie method or mix.
16 (232 g) Mint Oreos — 4 chopped into the batter for mix-ins, 12 left whole to press on top; they provide mint flavor and crunch.
1/4 cup (57 g) butter — melted and used in the espresso buttercream to add richness and shine.
1/4 cup (21 g) unsweetened cocoa powder — gives the buttercream real chocolate depth; whisk to remove lumps.
1 – 1 1/2 cups (113.5–170 g) confectioners’ sugar — sweetens and structures the frosting; add incrementally to reach the right consistency.
3 tablespoons (42 g) milk — thins and smooths the frosting; add in 1-tablespoon increments to control texture.
1/2 teaspoon (2 g) vanilla extract — rounds out the frosting flavor.
1/4 teaspoon (0.6 g) espresso powder — a small amount brightens the chocolate without adding overt coffee taste.

Directions: Chocolate Mint Brownies

Preheat the oven to 350°F (175°C). Spray a 9×13-inch baking dish with nonstick cooking spray and set aside.
Prepare the fudge brownie batter according to the Fudge Brownies Recipe, omitting any nuts called for in that recipe.
Break 4 Mint Oreos into large pieces and fold them evenly into the prepared brownie batter.
Pour the brownie batter into the prepared 9×13 pan and smooth the top. Arrange the remaining 12 Mint Oreos evenly on top of the batter.
Bake the brownies 45–50 minutes, until the center no longer moves when you gently shake the pan or a toothpick inserted in the center comes out with moist crumbs but no wet batter.
Remove the pan from the oven and let the brownies cool in the pan for 20–30 minutes.
While the brownies are baking, make the espresso buttercream: place the 1/4 cup (21 g) unsweetened cocoa powder in a large bowl or the bowl of a stand mixer and whisk to remove lumps.
Melt the 1/4 cup (57 g) butter and pour it into the bowl with the cocoa powder. Whisk until smooth and fully combined.
Add the confectioners’ sugar and milk to the cocoa-butter mixture in alternating small portions, using the amounts on the ingredient list: start with 1 cup (113.5 g) confectioners’ sugar, then add 1 tablespoon of the 3 tablespoons (42 g) milk and beat on high for about 1 minute. Continue adding the remaining confectioners’ sugar (up to a total of 1–1 1/2 cups / 113.5–170 g) in increments and the remaining milk (total 3 tablespoons) in 1-tablespoon increments, beating after each addition, until the frosting reaches a spreadable but firm consistency.
Add the 1/2 teaspoon (2 g) vanilla extract and the 1/4 teaspoon (0.6 g) espresso powder to the frosting and beat briefly to combine until smooth.
Once the brownies have cooled 20–30 minutes in the pan and are warm but not hot, spread the espresso buttercream evenly over the top.
Cut the brownies while still warm or after they come to room temperature and serve. Store any leftovers in an airtight container for up to one week.

Top Reasons to Make Chocolate Mint Brownies

High impact, low stress: The look of layered cookies and glossy frosting makes these feel special with relatively little extra work.
Texture contrast: Fudgy brownie, crunchy cookie, and creamy buttercream all in one bite keep things interesting.
Flavor balance: Mint and chocolate are classic partners; the espresso powder in the frosting amplifies chocolate notes without making it taste like coffee.
Great for sharing: A 9×13 pan feeds a crowd and transports well for potlucks or coffee dates.
Flexible base: Because the recipe builds on a Fudge Brownies Recipe, you can adjust chocolate intensity or mix-in strategy to suit your preferences.

Flavor-Forward Alternatives

Fold in more Mint Oreos instead of placing them on top for pockets of cookie throughout each square.
Swap the 12 top Oreos for a single, evenly spaced Oreo layer pressed slightly into the batter for a dramatic cross-section when sliced.
Omit the espresso powder in the buttercream if you prefer a pure chocolate-mint profile; the frosting will be sweeter and less bright.
Use a thicker layer of frosting (use toward the higher end of the confectioners’ sugar range) if you like a more frosting-forward bite.
If you want a smoother appearance, pulse leftover Oreos into coarse crumbs and sprinkle them over the frosting instead of placing whole cookies.

Must-Have Equipment

Oven set to 350°F (175°C) — accurate temperature is key for fudgy centers.
9×13-inch baking dish — the specified size ensures correct bake time and depth.
Nonstick cooking spray — for easy release and cleanup.
Mixing bowls — at least one large bowl for brownie batter and one for the frosting.
Whisk and/or electric mixer — a whisk removes lumps from cocoa; a hand or stand mixer speeds frosting assembly.
Rubber spatula — for folding Oreos into batter and for smoothing the top.
Measuring cups and spoons or a kitchen scale — the recipe mixes volume and weight; accuracy helps consistency.
Toothpick — for checking doneness in the center.

Pitfalls & How to Prevent Them

Undercooked center: If you remove the brownies too early they’ll be gummy. Test with a gentle shake of the pan and a toothpick; look for moist crumbs, not raw batter.
Overbaked, dry brownies: Watch the oven during the last 5–10 minutes and remove at the first sign the center has set. Carryover heat will finish the bake as they rest.
Soggy Oreos: If you press Oreos too far into the batter before baking they can become overly soft. Arrange the remaining cookies on top as directed to keep texture contrast.
Grainy or runny frosting: Add confectioners’ sugar in increments and beat between additions to monitor texture. If frosting is too thin, add a little more confectioners’ sugar; too stiff, add milk sparingly.
Frosting melts into brownies: Allow brownies to cool 20–30 minutes so they’re warm, not piping hot, before spreading the buttercream.

Smart Substitutions

No Mint Oreos? Use regular Oreos for a classic chocolate cookie bite; the result will be less mint-forward but still delicious.
If you don’t have espresso powder, omit it from the frosting — the cocoa and vanilla still produce a nicely flavored buttercream.
Butter in the frosting: if you only have salted butter, reduce any additional salt in your brownie base. The frosting will be slightly savory-sweet but still tasty.
Confectioners’ sugar range: start with 1 cup for a softer frosting and use up to 1 1/2 cups for a stiffer, more pipeable finish.
Milk alternatives: if you prefer a non-dairy milk for smoothing the frosting, use it in the same incremental way to reach the right texture.

Behind-the-Scenes Notes

I usually make the brownie batter first and get it in the pan, then use the baking time to prepare the coffee-chocolate buttercream. That overlap saves time and keeps the frosting fresh. The instruction to break 4 Oreos into large pieces and fold them in creates delightful textural surprises; don’t pulverize them — leave larger chunks so you get a contrast between soft brownie and crisp cookie.

When I test for doneness, I prefer the gentle-shake method combined with a toothpick. Brownies baked to a fudgy center will show moist crumbs, not raw batter, and will firm up as they cool. For cleaner slices, refrigerate briefly after the frosting sets — chilled brownies cut with a sharp knife give neater squares.

How to Store & Reheat

Room temperature: Store leftovers in an airtight container for up to one week, as noted in the directions. That keeps the frosting stable and the brownie chew intact.
Fridge: If your kitchen is warm or you prefer chilled bars, refrigerate for up to 5–7 days; bring to room temperature before serving for best texture.
Reheat single squares briefly in the microwave (8–12 seconds) to revive the fudgy quality; use shorter times to avoid melting the frosting completely.
For a gentle refresh, warm in a 300°F (150°C) oven for 6–8 minutes on a baking sheet; this warms the interior without overly softening the frosting.

Troubleshooting Q&A

Q: The center sank after cooling. A: The brownies were likely underbaked. Next time bake until a toothpick comes out with moist crumbs and allow the pan to rest for 20–30 minutes before cutting.
Q: My frosting is gritty. A: Make sure the cocoa powder was whisked to remove lumps and beat the butter and sugar thoroughly. Sift the confectioners’ sugar if you see clumps.
Q: Oreo pieces got mushy. A: Keep about 12 Oreos on top as whole cookies rather than pushing them deep into the batter; fold only 4 as the recipe directs to preserve texture.
Q: Frosting is too thin and slides off. A: Beat in a bit more confectioners’ sugar in small increments until it firms up; chill briefly before spreading if needed.
Q: Brownies stuck to the pan. A: Be generous with nonstick spray or line the pan with parchment, leaving an overhang for easy lifting.

Bring It Home

These Chocolate Mint Brownies are a dependable showstopper: fudgy base, minty cookie crunch, and a silky espresso-kissed frosting. Follow the exact ingredient list and the step-by-step directions, give the brownies their resting time, and you’ll serve squares with confident texture and layered flavor. Make them a day ahead for easy entertaining, and slice them warm or at room temperature depending on your preferred texture. If you make them, snap a photo and savor one with a glass of cold milk or a bold cup of coffee — they look as good as they taste.

Print Recipe Save it for later

Chocolate Mint Brownies Recipe

Chocolate mint brownies made with a fudge brownie base, Mint Oreos, and an espresso chocolate buttercream.

Prep Time10

Cook Time45

Total Time55

Course: Dessert

Servings: 16 servings

Ingredients

1 Fudge Brownies Recipe
16 232 gMint Oreos
1/4 cup 57 gbutter
1/4 cup 21 gunsweetened cocoa powder
1 – 1 1/2 cups 113.5-170 gconfectioners' sugar
3 tablespoons 42 gmilk
1/2 teaspoons 2 gvanilla extract
1/4 teaspoon 0.6 gespresso powder

Instructions

Preheat the oven to 350°F (175°C). Spray a 9×13-inch baking dish with nonstick cooking spray and set aside.
Prepare the fudge brownie batter according to the Fudge Brownies Recipe, omitting any nuts called for in that recipe.
Break 4 Mint Oreos into large pieces and fold them evenly into the prepared brownie batter.
Pour the brownie batter into the prepared 9×13 pan and smooth the top. Arrange the remaining 12 Mint Oreos evenly on top of the batter.
Bake the brownies 45–50 minutes, until the center no longer moves when you gently shake the pan or a toothpick inserted in the center comes out with moist crumbs but no wet batter.
Remove the pan from the oven and let the brownies cool in the pan for 20–30 minutes.
While the brownies are baking, make the espresso buttercream: place the 1/4 cup (21 g) unsweetened cocoa powder in a large bowl or the bowl of a stand mixer and whisk to remove lumps.
Melt the 1/4 cup (57 g) butter and pour it into the bowl with the cocoa powder. Whisk until smooth and fully combined.
Add the confectioners' sugar and milk to the cocoa-butter mixture in alternating small portions, using the amounts on the ingredient list: start with 1 cup (113.5 g) confectioners’ sugar, then add 1 tablespoon of the 3 tablespoons (42 g) milk and beat on high for about 1 minute. Continue adding the remaining confectioners’ sugar (up to a total of 1–1 1/2 cups / 113.5–170 g) in increments and the remaining milk (total 3 tablespoons) in 1-tablespoon increments, beating after each addition, until the frosting reaches a spreadable but firm consistency.
Add the 1/2 teaspoon (2 g) vanilla extract and the 1/4 teaspoon (0.6 g) espresso powder to the frosting and beat briefly to combine until smooth.
Once the brownies have cooled 20–30 minutes in the pan and are warm but not hot, spread the espresso buttercream evenly over the top.
Cut the brownies while still warm or after they come to room temperature and serve. Store any leftovers in an airtight container for up to one week.

Equipment

9x13 inch Baking Dish
nonstick cooking spray
large bowl or stand mixer
Whisk
Spatula
toothpick

Notes

12. Cut the brownies while still warm or after they come to room temperature and serve. Store any leftovers in an airtight container for up to one week.