Recipe Card

Preheat oven to 350°F. Line a 9×13-inch pan with foil and spray it with cooking spray.
Mix the Mint Filling: In medium bowl, stir together marshmallow fluff, mint extract, and food coloring; set aside.
Melt Chocolate: Microwave chocolate and butter in large bowl for 90 seconds until melted. Stir until smooth.
Combine Ingredients: Stir in sugar, then eggs and vanilla. Mix in flour until just combined, then fold in 12 crumbled Oreos.
Bake: Spread brownie batter in prepared pan and swirl in green filling. Bake for 23-25 minutes until set.
Cool: Cool completely for about 1 hour or in the freezer for 10 minutes.
Make Frosting: Whisk together butter, powdered sugar, vanilla, and milk until smooth. Melt white chocolate and mix with frosting and food coloring.
Frost and Crumble: Spread frosting over brownies and sprinkle with 18 crumbled Oreos. Allow to set before serving.