01 - Preheat oven to 350°F. Line a 9x13-inch metal baking pan with parchment paper, leaving an overhang for easy removal.
02 - Whisk together flour, cocoa powder, baking powder, and salt in a medium bowl. Set aside.
03 - In a large bowl, whisk melted butter with granulated sugar and brown sugar until smooth and glossy.
04 - Add eggs one at a time, whisking thoroughly after each addition. Stir in vanilla extract.
05 - Gently fold dry ingredients into wet mixture until just combined, avoiding overmixing.
06 - Fold in chocolate chips, reserving a small amount to sprinkle on top.
07 - Pour batter evenly into prepared pan. Sprinkle reserved chocolate chips on the surface.
08 - Bake for 28 to 32 minutes until edges are crisp and a toothpick near the edge comes out clean; center remains fudgy.
09 - Allow to cool completely in pan on a wire rack. Lift out using parchment, slice into 12 portions, and serve.