Preheat oven to 375 F. Line a cookie sheet with parchment paper or silplat mat.

Dry ingredients: flour, cocoa powder, baking powder, baking soda and salt in medium bowl; set aside.

Wet ingredients: butter, sugar and brown sugar in a separate mixing bowl and beat for a few minutes until creamed together. Add egg and vanilla and mix until combined.

Combine: Gradually mix in the flour mixture until combined. Stir in chocolate chips.

Refrigerate: Cover bowl and refrigerate dough for 30 minutes (or up to 3 days stored in an air-tight container).

Scoop dough using a 1/4 cup measuring cup to make them uniform in size. Place on a baking sheet 2 inches apart.

Bake for 12 to 15 minutes or until set around the edges (don't over bake!). Allow to cool for several minutes on the baking sheet before transferring to a wire rack to cool completely