How to Make It
Whisk together the flour, baking powder, salt, and baking soda in a medium mixing bowl until combined; set aside.
Using a stand mixer or electric hand mixer, cream the butter, brown sugar, and granulated sugar for 5 minutes, or until light and fluffy. Scrape down the sides and bottom of the bowl with a rubber spatula. Add the vanilla extract and egg; beat at medium-low speed until incorporated.
Add the flour mixture, beating at medium-low speed until incorporated. With a rubber spatula, mix in the chocolate chips by hand, scraping the sides of the bowl to incorporate any remaining flour. Cover the bowl and chill the dough 10-15 minutes (to make it easier to handle).
Scoop the dough into 6 equal portions. (You can use a heaping ½ cup measure to portion the dough into 6 mounds.) Place the mounds on a parchment paper lined baking sheet, cover with plastic wrap, and refrigerate 3 hours, or up to overnight.
Preheat oven to 400°F.
Arrange 3 portions of dough on a parchment paper-lined sheet pan (keep remaining dough portions refrigerated). Bake 400°F for 15-18 minutes or until cookies are golden-brown and appear set, rotating pan after 10 minutes. Repeat process with remaining 3 portions of dough. Cool the cookies on the sheet pan for 10 minutes before transferring to a wire rack to cool completely, at least 30 minutes.