Chocolate Chip Cookie (Copycat Levain Bakery Classic)

1 cup 2 sticks cold unsalted butter, cubed
½ cup granulated sugar
1 cup brown sugar packed
2 large eggs
3 cups all-purpose flour or 1½ cups all-purpose + 1½ cups cake flour
1 teaspoon corn starch
¾ teaspoon baking soda
¾ teaspoon salt
2 cups chocolate chips mix of semi-sweet, milk chocolate, and chunks, if you like
1½ to 2 cups chopped pecans or walnuts

Cream the Butter & Sugars Start with cold, cubed butter and blend with sugars in a stand mixer for 3–4 minutes, until smooth and creamy.
Add Eggs Mix in eggs one at a time, scraping the bowl to make sure everything comes together evenly.
Mix Dry Ingredients Whisk flour, corn starch, baking soda, and salt. Add gradually to the wet mixture on low speed. Scrape down the bowl for even dough.
Stir in Chocolate & Nuts Fold in the chocolate chips and chopped nuts, aiming for even distribution.
Shape & Bake Scoop large balls of dough (think bakery-sized!) onto a parchment-lined tray. Bake at 400°F for about 9–10½ minutes, until golden on the edges and soft in the center.
Finishing Touches Fresh from the oven, press a few extra chocolate chunks into the tops and sprinkle with flaky salt. Let cool slightly, then share (or savor warm!).