01 - Preheat oven to 350°F. Grease a 24-cup mini muffin tin or line with mini cupcake liners.
02 - In a medium bowl, whisk together flour, cocoa powder, baking powder, and salt until evenly blended.
03 - In a large bowl, whisk the melted butter and granulated sugar until smooth. Add eggs one at a time, whisking thoroughly after each addition. Stir in vanilla extract.
04 - Fold the dry mixture into the wet ingredients just until combined; avoid overmixing to maintain a tender texture.
05 - Gently fold in the semi-sweet chocolate chips or chunks to distribute evenly.
06 - Spoon the batter evenly into the prepared mini muffin cups, filling each about three-quarters full.
07 - Bake for 12 to 15 minutes, or until tops are set and a toothpick inserted into the center comes out with moist crumbs.
08 - Allow the brownie bites to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.