Start by browning half of the butter until it smells nutty and golden. Keep the other half softened for creaming with sugar. This combo creates depth of flavor and the perfect cookie texture.
Cream the softened butter with dark brown and white sugar until fluffy. Add eggs and vanilla, then gradually fold in all flours, salt, baking powder, and chocolate pieces. The dough should be thick and rich.
Chill the dough using the double-chill method: first for 1–2 hours, then scoop into balls and chill again before baking. This prevents spreading and gives the cookies their signature height.
Preheat oven to 350°F (175°C). Place cookie dough balls on a lined baking sheet and bake for 12–15 minutes. The edges should be golden while the center stays soft and tender.