01 - Preheat the oven to 350°F. Grease a 24-cup mini muffin tin with cooking spray or butter, or line with mini paper liners for easy removal.
02 - Set up a double boiler by placing a heatproof bowl over a pot of simmering water. Add butter and chopped chocolate, stirring constantly until completely melted and smooth. Remove from heat and cool for 5 minutes.
03 - Whisk sugar into the melted chocolate mixture until dissolved. Add eggs one at a time, beating well after each addition. Stir in vanilla and peppermint extract until fully incorporated.
04 - Sift flour, cocoa powder, and salt directly into the wet mixture. Using a rubber spatula, fold gently until no dry streaks remain. Be careful not to overmix—the batter should be thick and glossy.
05 - Portion batter into prepared muffin cups, filling each about 3/4 full. Bake for 12–15 minutes until tops appear set and a toothpick inserted in the center comes out with moist crumbs, not wet batter.
06 - Let the bites cool in the tin for 5 minutes to set structure. Carefully transfer to a wire rack and cool completely before applying ganache, about 30 minutes.
07 - Place finely chopped chocolate in a heat-resistant bowl. Heat heavy cream in a small saucepan until just steaming and bubbles form around the edges—do not let it boil. Pour hot cream over chocolate and let stand for 1 minute.
08 - Add peppermint extract to the chocolate-cream mixture. Stir gently with a spatula starting from the center, working outward until completely smooth and glossy. Let ganache cool for 5 minutes to thicken slightly.
09 - Spoon or pipe ganache onto each cooled brownie bite. Garnish with fresh mint leaves or chocolate shavings if desired. Allow ganache to set for 15–20 minutes at room temperature before serving.