Preheat your oven to 350°F (175°C). Prepare a mini muffin tin by lining it with paper liners or lightly greasing each cup to prevent sticking.
In a large mixing bowl, combine the unsweetened cocoa powder, all-purpose flour, granulated sugar, packed brown sugar, baking powder, and salt. Whisk the dry ingredients together thoroughly until evenly blended.
In a separate mixing bowl, mix the melted unsalted butter, large eggs, vanilla extract, and peppermint extract. Stir until the mixture is smooth and well combined.
Gradually add the wet ingredients to the bowl with the dry ingredients. Use a spatula to gently fold them together until just combined, being careful not to overmix for a fudgy texture.
Carefully fold in the dark chocolate chips and chopped fresh mint leaves until they are evenly distributed throughout the batter.
Spoon the batter into the prepared mini muffin tins, filling each cup about three-quarters full to allow room for rising.
Place the muffin tin in the preheated oven and bake for 12 to 15 minutes. Check for doneness by inserting a toothpick into the center of one brownie bite; it should come out clean.
After baking, let the brownie bites cool in the tin for about 5 minutes. Then, transfer them to a wire rack to cool completely before serving.
Once the brownie bites have cooled, dust them lightly with powdered sugar to add an elegant touch.
Notes
Serve on a decorative plate with fresh mint for garnish.
Keyword bite-sized, brownies, chocolate, dessert, mint