01 - Preheat oven to 375°F. Line two baking sheets with parchment paper.
02 - Whisk together flour, cocoa powder, baking soda, baking powder, and salt in a large bowl until well combined.
03 - Whisk melted butter, granulated sugar, and brown sugar until smooth. Add eggs and vanilla extract, whisking until fully incorporated.
04 - Alternately add dry ingredients and milk to wet mixture, starting and ending with dry ingredients. Mix gently until just combined—do not overmix.
05 - Fold in chocolate chips until evenly distributed throughout batter.
06 - Using a large cookie scoop or 1/4 cup measure, drop mounds of batter onto prepared baking sheets, spacing 2 inches apart. Gently shape into rounds and sprinkle extra chips on top if desired.
07 - Bake for 10 to 12 minutes until tops are set and slightly cracked but still soft in center.
08 - Let cool on baking sheet for 5 minutes, then transfer to wire rack to cool completely.