1. In a medium bowl, whisk together flour, cocoa powder, baking powder, and salt. Set aside.

2. In a large bowl, cream together softened butter, granulated sugar, and brown sugar until light and fluffy.

3. Add eggs one at a time, beating well after each addition, then stir in the vanilla extract.

4. Gradually add the dry ingredients to the wet mixture, mixing until just combined.

5. Fold in the chocolate chips using a spatula or on low mixer speed.

6. Cover the dough and refrigerate for at least 2 hours or overnight.

7. Preheat oven to 350°F (175°C) and line baking sheets with parchment paper.

8. Roll chilled dough into 1 to 1.5 inch balls, then coat generously in powdered sugar.

9. Place on baking sheet 2 inches apart and bake for 10–12 minutes.

10. Let cool on the sheet for 5 minutes, then transfer to a wire rack to cool completely.