01 - Preheat oven to 375°F. Line two baking sheets with parchment paper.
02 - In a large bowl, whisk melted butter, granulated sugar, and brown sugar until smooth. Beat in eggs one at a time, then add milk and vanilla, mixing until well combined.
03 - In a separate bowl, whisk flour, cocoa powder, baking powder, baking soda, and salt until evenly combined.
04 - Gently stir dry ingredients into wet ingredients until just combined; avoid overmixing.
05 - Fold semisweet chocolate chips into the batter gently.
06 - Using a large cookie scoop or two spoons, drop 1/4 cup portions of batter onto prepared baking sheets, spacing at least two inches apart.
07 - Sprinkle additional chocolate chips atop each batter mound.
08 - Bake for 10 to 12 minutes until tops are set but centers remain soft.
09 - Allow to cool on the baking sheet for five minutes before transferring to a wire rack to cool completely.