Preheat the oven to 350 degrees
Tear a piece of parchment paper off that will cover the whole bottom of the glass pan and slightly come up the sides
Follow the directions on the back of the brownie box and once baked, allow to completely cool
Once cooled, using a standing mixer, combine the butter, powder sugar, peppermint extract and heavy whipping cream.
Mix on medium speed until combined and stiff peaks form.
Spread the frosting onto the cooled brownies
Place the frosted brownies into the fridge for about an hour for the frosting to harden.
Once frosting is harden, place the 8 oz of semi sweet chocolate chips and 1 C of heavy whipping cream in a medium bowl
Place bowl into the microwave for 45 seconds
Using a whisk, mix until combined and smooth.
Pour ganach over the frosting and sprinkle the crushed candy canes.
Place back into the fridge for 2 hours before enjoying!