1. Prepare your oven and a 9×13 inch baking pan (or size recommended by your brownie mix box) by greasing and flouring, or lining with parchment paper. Prepare the 16-ounce box brownie mix according to the package directions, using the specified water, eggs, and oil. Pour the batter into the prepared pan and bake as directed by the box mix, typically for 25-30 minutes, or until a toothpick inserted near the center comes out with moist crumbs. Do not overbake. Allow the brownies to cool completely in the pan on a wire rack, which can take 1-2 hours. This step is crucial for perfect frosting application.

2. While the brownies cool, prepare the peppermint frosting. In a large mixing bowl, beat the softened ¾ cup unsalted butter with an electric mixer until light and fluffy (about 2-3 minutes). Gradually add the 2 cups confectioner’s sugar, beating until fully incorporated. Add 2 tablespoons of heavy whipping cream and continue to beat until the frosting is smooth and creamy. Fold in ½ cup of finely crushed candy canes and 2 drops of red food coloring (if desired for a festive pink hue). Mix until just combined. Taste and adjust peppermint level if you wish to add a tiny bit of peppermint extract (start with ¼ teaspoon).

3. In a small saucepan, heat 1 cup heavy whipping cream over medium heat until it just begins to simmer around the edges. Do not boil. Remove from heat and immediately pour over 2 cups of semi-sweet chocolate chips in a heatproof bowl. Let sit undisturbed for 5 minutes to allow the chocolate to melt. Whisk gently from the center outwards until the ganache is smooth, shiny, and fully emulsified. Let the ganache cool slightly, about 10-15 minutes, to thicken to a pourable consistency.

4. Once the brownies are completely cool, spread the peppermint buttercream frosting evenly over the top using an offset spatula. Then, carefully pour or spread the slightly cooled chocolate ganache over the peppermint frosting layer. The ganache should be warm enough to spread but not so hot that it melts the frosting completely. Finally, immediately sprinkle the remaining ½ cup of crushed candy canes over the wet ganache layer to ensure they adhere. Allow the ganache to set, either at room temperature (1-2 hours) or in the refrigerator (30 minutes) before cutting.

5. Once the ganache has set, use a sharp knife (wiped clean between each cut for neat edges) to slice the brownies into 20 squares. Serve and enjoy your festive Peppermint Brownies!