These Mint Oreo Brownies are layered to perfection with marshmallow cream swirls, minty marshmallow buttercream, and a generous topping of Mint Oreos. Together, they create the most scrumptious, fudgy, and minty brownie treat perfect for St. Patrick’s Day.

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Mint Oreo Brownies

St. Patrick’s Day is just a week away and this redheaded Irish girl couldn’t be more excited!

I’m mean, what’s not to love? Green beer (heck, I usually don’t even like beer!), corned beef and cabbage, “Kiss me I’m Irish” shirts, etc. And of course, these delicious, fudgy, mint Oreo brownies. And not just any mint Oreo brownies, brownies with marshmallow swirls, creamy mint buttercream frosting, and a crushed Mint Creme Oreo topping. I’m drooling just thinking about them.

It’s also my mom’s birthday, so it’s like a double whammy holiday with even more festivities. I even remember when she snuck me out of school when I was younger to take me to the St. Patty’s Day parade. Crazy, fun (and probably drunk), Irish people > school any day!

Now back the brownies… I don’t care if you’re Irish or not, everyone gets to partake in St. Patrick’s Day celebrations. And I guarantee you’ll be everyone’s favorite Irishman/Irishwoman (or honorary Irishman) if you show up with a giant pan of these fudgy minty green goodness brownies.

What makes these brownies so good is that each layer is delicious on its own but so rich and decadent when layered together.

  • Fudge brownies with melty chocolate chips and Mint Creme Oreo chunks
  • Minty marshmallow creme swirls
  • Minty marshmallow buttercream
  • And crumbled Mint Creme Oreos sprinkled on top

Sure, they’re not quite as healthy (or even a little bit healthy for that matter) as other green foods like salad or green smoothies. But I can assure you they are 100% worth it!

I’ll be honest, I love to bake and experiment with recipes, but I usually use a boxed brownie mix. First, it’s way faster and easier with all the dry ingredients premixed. Second, it’s cheap and convenient. And finally, I’ve never made a homemade brownie recipe that’s exponentially better than a box to justify the extra time or mess.

My Favorite Brownie Mix

I usually use a box of Ghirardelli brownie mix from Costco or even a Fudge Brownie mix from Aldi (less than $1!). I know it feels like cheating when you don’t make them from scratch, but once you doctor up boxed brownies like this, no one will ever know.


How to Make Mint Oreo Brownies

Marshmallow Swirl

Mix the entire 7oz. jar of marshmallow creme with a few drops of mint or peppermint extract. Warning! A little goes a long way! Start with 3 drops, taste, and add 1 drop at a time until it’s the right level of mintiness. There’s a fine line between a pleasant hint of festive mint flavor and mouthwash-level mintiness!

Prepare brownie mix

Stir in 10 coarsely crushed Cool Mint Oreos, then Pour into a greased 9x13 and smooth out until even. Next, scoop dollops of the marshmallow mixture (only use half, reserve the other half for the buttercream) on top of the brownie batter and swirl into the batter with a butter knife. Bake in a preheated oven for 25 minutes. When brownies are cooked through (and pass the toothpick test), place on a rack to cool.

Minty Marshmallow Butter Cream

Cream the room temperature butter with powdered sugar 1 cup at a time until well incorporated. After 3 cups of powdered sugar, add ¼ cup at a time so it doesn’t get too thick. Don’t worry if it does, a tablespoon or 2 of milk will thin it back to frosting consistency. Next, whisk in the reserved marshmallow swirl. Taste it again to see if it needs more peppermint extract and add 1 drop at a time. Finally, add a few drops of green food coloring to achieve the perfect minty green color.

Once the brownies are cooled, spread the buttercream evenly across the top. Finally sprinkle 10 coarsely chopped Mint Creme Oreos over the frosting, pressing down gently so they’ll stick to the frosting.

Need an easy way to transport these Mint Oreo Brownies? This Anchor Hocking Tote Bakeware set is my favorite (and it’s held up for the last 7 years I’ve owned it)!

What is your go-to St. Patrick’s Day celebratory food? If you try these Mint Oreo Brownies, snap a pic and tag me over on Instagram!