Levain Chocolate Chip Cookies: Golden

Instructions:

1. In a bowl, cream the cold, cubed butter with the granulated and brown sugars on medium-high until combined but still thick and gritty.
2. Add the cold eggs one at a time and stir in the vanilla extract.
3. In a separate bowl, whisk together the flour, cornstarch, baking soda, and salt.
4. Gradually add the dry ingredients to the butter mixture on low speed, mixing until just combined to avoid developing too much gluten.
5. Fold in the semi-sweet chocolate chips, dark chocolate chunks, and toasted walnuts.
6. Divide the dough into 8 large portions (approximately 6oz each) and chill in the refrigerator for 1 hour.
7. Place chilled dough mounds on a baking sheet lined with parchment paper and bake at a high temperature for 15 minutes until the exterior is mahogany-colored but the center remains gooey.