(approx. 18 cookies)
Preheat the oven to 180 °C (356 °F, top and bottom heat) and line a baking tray with parchment paper.
Beat the butter, brown sugar, and granulated sugar until light and fluffy (2–3 minutes), until pale in color.
Beat in the egg and vanilla extract. You now have your “wet ingredients.”
In a separate bowl, mix together the flour, baking soda, baking powder, and salt. Add the dry mixture to the wet ingredients and mix just until combined.
Stir in the chocolate pieces.
Refrigerate the dough for at least 30 minutes. It will hold its shape better and the flavor will be more intense.
Form balls about the size of a heaping tablespoon (approx. 35–40 g). Place them on the baking tray with plenty of space between them, as they will spread while baking.
Bake for 9–11 minutes. The edges should be golden, while the center should still be soft and slightly underbaked — it will finish baking on the tray.
Leave the cookies on the tray for about 5 minutes, then transfer them to a wire rack to cool completely.