Step 1

If baking right away, preheat oven to 350ºF. Line baking sheets with nonstick baking mats or parchment paper.

Step 2

In a medium bowl, whisk together the flours, baking soda, baking powder, and salt.

Step 3

In the bowl of an electric mixer, beat the butter, granulated sugar, and brown sugar on medium-high speed until light and fluffy, about 2-3 minutes. Add the eggs and yolk, one at a time, beating well after each addition. Add the vanilla. Slowly beat in the flour mixture. Stir in the chocolate chips.

Step 4

If time permits, wrap dough in plastic wrap and refrigerate for at least 24 hours but no more than 72 hours. This allows the dough to “marinate” and makes the cookies thicker, chewier, and more flavorful. Let dough sit at room temperature just until it is soft enough to scoop.

Step 5

Using a large spring-loaded scoop, divide the dough into 3-tablespoon sized balls and drop onto prepared baking sheets.

Step 6

Bake for 12-15 minutes, or until golden brown. Cool for 2 minutes before removing to wire racks to cool completely.

Step 7

Although I prefer cookies fresh from the oven, these can be stored in an airtight container for up to 3 days. See post for storage tips.