Preheat the oven to 350°F (180°C). Line 3 baking sheets with parchment paper (if you only have two sheets, just re-use the sheet from the first batch you bake; no need to change the paper).

Add the butter and sugars to a deep bowl. Beat until smooth and creamy.

Meanwhile, add the flours, baking soda, and salt to a small bowl. Whisk to blend.

Add the egg and vanilla to the butter-sugar mixture. Beat on medium speed until well-blended and fluffy, about 1 minute.

Add the flour mixture. Starting on low speed, mix just until incorporated, and there are no visible signs of flour.

Add the chocolate chips, and beat just until they're mixed in, about 30 seconds. Transfer the dough to a container, cover, and let sit in the fridge overnight, and up to 48 hours.

When ready to bake, drop tablespoons of dough (see note below) onto the prepared baking sheets, spacing the dough mounds 2 inches (5 cm) apart. Bake, one sheet at a time (important for cookies to cook evenly!), until the bottoms and edges are lightly browned and the tops look set, 10-12 minutes (I opt for less time for a super chewy cookie). Let the cookies cool on the baking sheets for 5 minutes, then transfer the cookies to wire racks to cool completely.

Note: You can freeze any remaining cookie dough for future enjoyment. To do so, line a baking sheet with waxed paper. Scoop the dough into balls, and set the pan in the freezer until the dough is firm. Transfer to an air tight container or bag. The cookies may be baked straight from the freezer.