01 -
Preheat the oven to 175°C. Line a 23 cm x 23 cm square baking pan with parchment paper and set aside.
02 -
Prepare the brownie mix according to the package instructions. Fold in the finely chopped Oreo cookies until evenly distributed.
03 -
Spread the batter evenly in the prepared pan. Bake as directed on the brownie mix packaging, typically 20-25 minutes, or until a toothpick inserted in the centre comes out with moist crumbs.
04 -
Remove from the oven and let cool at room temperature for 5 minutes. Place in the freezer to cool further while preparing the mint frosting.
05 -
In a mixing bowl, beat together the softened cream cheese and butter until smooth and creamy. Mix in peppermint extract and a small amount of green food colouring until uniformly tinted. Gradually add powdered sugar, beating well until the mixture is fluffy and spreadable.
06 -
Spread the mint frosting evenly over the cooled brownie layer. Return the pan to the freezer while the ganache is prepared.
07 -
Place chocolate chips in a heatproof bowl. In a separate microwave-safe bowl, heat the heavy cream and butter together for 60 seconds until very hot but not boiling. Pour the hot mixture over the chocolate chips, cover, and let stand for 5 minutes.
08 -
After 5 minutes, whisk the chocolate mixture until glossy and completely smooth. Allow ganache to set at room temperature 10–15 minutes to thicken slightly.
09 -
Remove the pan from the freezer. Pour ganache over the frosted brownies, spreading smoothly to the edges.
10 -
Allow brownies to sit at room temperature for 30 minutes to set the ganache. Refrigerate for 2–3 hours until fully set before slicing and serving.