Preheat the oven to 350°F. Line baking sheets with parchment paper and set aside.
In a large bowl, whisk the flour, cornstarch, baking soda, and salt.
3 cups all-purpose flour, 2 tablespoons cornstarch, 1 teaspoon baking soda, 3/4 teaspoon fine sea salt
In a stand mixer fitted with the paddle attachment, beat the butter and both sugars for about 3 minutes until light and fluffy.
1 cup unsalted butter, 3/4 cup granulated sugar, 3/4 cup light brown sugar
Add the eggs one at a time, mixing well after each addition. Stir in the vanilla.
2 large eggs, 1 tablespoon vanilla extract
Add the dry ingredients and mix on low speed until the dough comes together. Scrape the bowl as needed.
Set aside 1/2 cup of chocolate chunks. Stir the remaining chunks into the dough.
1 bag semi-sweet chocolate chunks
Divide the dough into 18 portions, about 2.5 ounces each.
Roll each portion into a ball and place on the baking sheets about 4 inches apart.
Press the reserved chocolate chunks into the tops of the dough balls.
Bake for 12-13 minutes until the cookies are puffed, set in the center, and lightly golden on the edges.
Sprinkle with flaky sea salt, if using. Let the cookies cool completely on the baking sheet.
Maldon flake sea salt
Notes
🥡 STORAGE: Store at room temperature for up to 5 days.Keep cookies in an airtight container to prevent them from drying out.♨️ REHEATING: Microwave for 10 seconds for a warm cookie.Warm in a 350°F oven for about 3 minutes.❄️ FREEZING: Freeze baked cookies for up to 3 months.Freeze dough balls on a baking sheet, then store in freezer bags.💡 TIPS FOR BEST RESULTS: Measure flour correctly to avoid dry cookies.Press extra chocolate on top for a bakery look.Rolling the dough into smooth balls helps the cookies bake evenly.🍳 ALTERNATE COOKING METHODS: Air fryer: Bake dough balls at 320°F for 6-8 minutes.Toaster oven: Bake at 350°F, but check early since they brown faster.♻️ LEFTOVERS: Crumble leftover cookies over ice cream.Use in parfaits or milkshakes.📝 NOTES: Try other extracts, such as peppermint, almond, strawberry, or coffee.Cornstarch keeps the cookies soft.Flaky salt adds a sweet-salty balance.Press a few extra chocolate chunks on top before baking for a bakery-style look.Add-ins like nuts, toffee, or flavored chips work well.Let the cookies cool on the baking sheet so the centers set without overbaking.