1-Preheat the oven: Preheat oven to 375°F and line a baking sheet with parchment paper.

2-Cream butter and sugars: Beat softened butter, brown sugar, and granulated sugar on medium speed until light and fluffy, about 2-3 minutes.

3-Add eggs and vanilla: Add eggs and vanilla extract, then beat until well combined, scraping the bowl as needed.

4-Whisk dry ingredients: In a separate bowl, whisk together flour, cornstarch, baking soda, and salt.

5-Combine dry and wet: Add dry ingredients to the wet mixture gradually, mixing on low speed just until combined; do not overmix.

6-Fold in chocolate chips: Stir in milk chocolate chips by hand with a spatula until evenly distributed.

7-Scoop large cookies and bake: For large Crumbl-style cookies, scoop 1/3 cup dough per cookie onto the prepared sheet and bake 10-11 minutes.

8-Scoop regular cookies and bake: For regular-sized cookies, use a medium ice cream scoop and bake 8 minutes.

9-Bake and cool: Bake until edges are golden and centers are slightly firm but soft; do not overbake. Let cookies rest on the baking sheet for 5 minutes before transferring to a cooling rack.