Levain Chocolate Chip Cookies for 12

Instructions:

1. Beat the cold, cubed butter with the brown sugar and granulated sugar on medium-high speed until combined but not overly fluffy.
2. Beat in the cold eggs one at a time, then stir in the vanilla extract until just incorporated.
3. Whisk together the flour, cornstarch, baking powder, baking soda, and salt in a separate bowl.
4. Gradually add the dry mixture to the butter mixture on low speed, mixing only until no streaks of flour remain.
5. Fold in the chocolate chips and walnuts by hand using a spatula.
6. Divide the dough into 12 equal portions (roughly 4 oz each) and shape them into tall, shaggy mounds.
7. Place the mounds on a tray and refrigerate for 2 hours.
8. Preheat the oven to 410°F (210°C).
9. Place the chilled mounds on a parchment-lined baking sheet, leaving ample space between them.
10. Bake for 12–15 minutes until the edges are deep golden brown and the centers still look slightly soft.
11. Allow the cookies to cool on the pan for 15 minutes to set the structure.