01 - Preheat oven to 350°F. Grease a 24-cup mini muffin tin or line with mini paper liners.
02 - Melt butter in a microwave-safe bowl. Stir in granulated and brown sugars until blended.
03 - Whisk in eggs, vanilla extract, and peppermint extract until smooth.
04 - Sift cocoa powder, flour, and salt into the wet mixture. Mix until just combined, then fold in mini chocolate chips.
05 - Spoon batter evenly into prepared mini muffin cups, filling each about three-quarters full.
06 - Bake for 12 to 15 minutes, or until a toothpick inserted in the center comes out with moist crumbs. Avoid overbaking.
07 - Let brownies cool in the tin for 10 minutes before transferring to a wire rack to cool completely.
08 - Heat heavy cream in a small saucepan until just simmering. Pour over chopped chocolate in a heatproof bowl. Let sit for 2 minutes, then stir until smooth. Stir in peppermint extract.
09 - Spoon or pipe ganache onto cooled brownie bites. Sprinkle with crushed peppermint candies if desired.
10 - Allow ganache to set at room temperature or refrigerate briefly before serving.