Ingredients
Equipment
Method
Prepare for Baking
- Preheat your oven to 350°F. Line a 9x13-inch pan with aluminum foil, allowing some overhang on the sides for easy removal. Spray the foil with cooking spray to prevent sticking.
- In a medium bowl, stir together the 7-ounce jar of marshmallow fluff, the precise ⅛ teaspoon of mint extract, and 4 drops of green food coloring. Continue adding drops until a light green is achieved. Set this mixture aside.
Brown the Butter for Brownie Base
- In a large microwave-safe bowl, melt the ¾ cup of unsalted butter. Continue to gently heat the butter, either on the stovetop over medium heat or in the microwave in short bursts, stirring frequently.
- Watch for golden brown flecks to appear at the bottom and a rich, nutty aroma to emerge. Be careful not to burn it. This process typically takes about 5-8 minutes on the stovetop or 2-4 minutes in the microwave. Once browned, let it cool slightly.
Mix the Brownie Batter
- To the still warm browned butter in the large microwave-safe bowl, add the 4 ounces of baking chocolate. Stir until the chocolate is completely melted and the mixture becomes glossy and smooth.
- Stir in the granulated sugar; it will still seem very granular, which is normal. Stir in the eggs one at a time, followed by the vanilla extract.
- If you are adding the optional espresso or brewed coffee, mix it in now. Stir in the all-purpose flour until it is just combined. Be careful not to overmix, as overmixing can lead to tough brownies.
Add Oreos and Swirl
- Hand-crumble 12 Cool Mint Oreo Cookies directly over the brownie batter and gently fold them in. Spread the prepared brownie batter evenly into your foil-lined 9x13-inch pan.
- Drop about ½ cup of the reserved green minty marshmallow mixture onto the brownie batter. Take a table knife and gently pull it through the batter in S-shaped curves to create a beautiful swirled design.
Bake the Brownies
- Bake for 23 to 25 minutes, or until the brownies are set. You are looking for a slight jiggle in the center and a toothpick inserted a few inches from the edge to come out with moist crumbs, not wet batter. Do not overbake for the fudgiest results.
Cool Completely
- Cool the brownies completely in the pan for about 1 hour. If in a rush, place the pan into the freezer for 10 minutes to speed up cooling. The brownies should feel cool to the touch before proceeding.
Prepare the Frosting and Assemble
- While the brownies are cooling, make the vanilla frosting. Whisk together the softened ½ cup butter or margarine, 3 to 4 cups of powdered sugar, and 1 teaspoon of vanilla extract. Add a splash of milk if necessary, until the mixture is smooth and fluffy. An electric mixer works wonders for this. (Optionally, use 1 cup of store-bought vanilla frosting).
- In another small microwave-safe bowl, melt the ¾ cup white chocolate chips. Microwave on high for 30 seconds, stir, then microwave for another 30 seconds. Stir until smooth, being careful not to scorch the white chocolate.
- Add the melted white chocolate chips and the prepared vanilla frosting to the reserved green minty marshmallow mixture. Stir in an additional 4 drops of green food coloring, or until your desired light green color is reached. Spread this vibrant minty frosting evenly over the completely cooled brownies.
Finishing Touch and Setting
- Sprinkle the 18 hand-crumbled Cool Mint Oreo Cookies over the top layer, gently pressing them into the green mixture. Allow this top layer to set fully before slicing and serving to ensure clean, beautiful cuts.
Nutrition
Notes
These Triple Layer Fudgy Mint Oreo Brownies are best served chilled, which enhances their rich fudgy texture and firms up the creamy mint frosting. For truly picture-perfect, clean slices, chill the entire finished product for at least 2-4 hours, or even overnight, before cutting. Store in an airtight container in the refrigerator for 5-7 days or freeze for up to 2-3 months. Nutrition information is estimated based on common ingredients and serving sizes and may vary.