Cream the Butter and Sugars: In a large mixing bowl, use an electric mixer to cream together the softened butter, brown sugar, and granulated sugar until the mixture is light and fluffy. This step is key to achieving the right cookie texture.

Add the Egg and Vanilla: Beat in the egg and vanilla extract until well combined, ensuring a smooth and consistent mixture.

Combine the Dry Ingredients: In a separate bowl, whisk together the all-purpose flour, cornstarch, baking soda, and salt. The cornstarch helps create a soft and chewy texture.

Mix Wet and Dry Ingredients: Gradually add the dry ingredients to the wet mixture, mixing on low speed until just blended. Be careful not to overmix, which can make the cookies tough.

Stir in the Chocolate Chips: Fold in the chocolate chips, ensuring they’re evenly distributed throughout the dough.

Chill the Dough: Cover the dough and chill it in the refrigerator for at least 30 minutes. Chilling helps prevent the cookies from spreading too much while baking, giving them a thicker texture.

Preheat the Oven: Preheat your oven to 350°F (175°C). Line your baking sheets with parchment paper to prevent sticking and make cleanup easier.

Drop the Dough: Scoop tablespoonfuls of dough onto the prepared baking sheets, spacing them about 2 inches apart to allow for spreading.

Bake to Perfection: Bake the cookies for 8-10 minutes, or until the edges are just beginning to turn golden. The centers may look slightly underdone, but they will continue to set as they cool.

Cool and Enjoy: Let the cookies cool on the baking sheets for 2 minutes before transferring them to wire racks to cool completely. This helps them maintain their shape and texture.