In a medium bowl, whisk together the flour, baking powder, baking soda, and salt until evenly combined.

In a large mixing bowl, beat the butter until light and fluffy, then gradually add the granulated and brown sugars.

Beat in the eggs one at a time, followed by the vanilla extract.

Gradually add the dry ingredients to the wet mixture, stirring gently until just combined.

Fold in the semi-sweet and milk chocolate chips.

Wrap the dough in plastic wrap and chill in the refrigerator for 24-36 hours.

Preheat your oven to 350°F (or 325°F for softer cookies). Prepare baking sheets with parchment paper.

Scoop and roll large tablespoons of dough into balls and place them on the prepared baking sheets.

Bake in the preheated oven for 9-11 minutes, until edges are lightly golden.

Cool on the baking sheet for 5 minutes before transferring to wire racks.