01 - Preheat oven to 350°F. Grease a 24-cup mini muffin tin or line with mini paper liners.
02 - Melt butter in a medium saucepan over low heat or microwave; allow to cool slightly.
03 - In a large bowl, whisk together melted butter, granulated sugar, and brown sugar until smooth.
04 - Whisk in eggs, vanilla extract, and peppermint extract until thoroughly combined.
05 - Sift in cocoa powder, flour, baking powder, and salt; stir gently until just combined to avoid overmixing.
06 - Fold mini chocolate chips evenly into the batter.
07 - Divide batter evenly among muffin cups, filling each about three-quarters full.
08 - Bake 16 to 18 minutes until centers are set and toothpick inserted comes out with moist crumbs.
09 - Allow to cool in the tin for 10 minutes before transferring to a wire rack to cool completely.
10 - Whisk powdered sugar, 1 tablespoon milk, and peppermint extract in a small bowl until smooth; add more milk as needed for desired pourable consistency.
11 - Drizzle glaze over cooled brownie bites, immediately sprinkle with crushed peppermint candies; let glaze set before serving.