Preheat oven to 375°F (190°C). Line a baking sheet with parchment paper.

In a large bowl, cream together butter, brown sugar, and granulated sugar until light and fluffy (about 2–3 minutes).

Add eggs and vanilla extract; beat until combined.

In a separate bowl, whisk together flour, cornstarch, baking soda, baking powder, and salt.

Gradually add the dry ingredients to the wet ingredients, mixing just until combined.

Stir in the milk chocolate chips.

Scoop dough into large balls using a ¼ cup measuring cup or large cookie scoop.

Chill dough balls in the refrigerator for 30 minutes.

Place dough balls onto the prepared baking sheet, leaving space between each cookie.

Bake for 10–12 minutes or until edges are golden and centers look slightly underbaked.

Let cookies rest on the baking sheet for 10 minutes before transferring to a wire rack to cool.