01 - Preheat the oven to 350°F. Line an 8-inch square baking pan with parchment paper, leaving an overhang to facilitate removal.
02 - Combine butter and chopped chocolate in a microwave-safe bowl; heat in 30-second increments, stirring until fully melted and smooth. Allow to cool slightly.
03 - Whisk granulated sugar, eggs, vanilla extract, and peppermint extract into the melted chocolate mixture until uniform.
04 - Sift together flour, cocoa powder, and salt; gently fold into the wet mixture until just combined to avoid overmixing.
05 - Transfer batter to the prepared pan and smooth the surface. Bake for 28 to 32 minutes, testing doneness with a toothpick—should have moist crumbs attached.
06 - Allow brownies to cool fully in the pan on a wire rack before glazing.
07 - Whisk powder sugar, milk, and peppermint extract until smooth. Add food coloring if desired.
08 - Evenly spread the glaze over the cooled brownies and sprinkle with crushed peppermint candies.
09 - Let the glaze set for 20 minutes, then lift brownies from the pan using parchment overhang and cut into 16 squares.