1-First, combine the melted butter with both sugars and mix vigorously for 2 minutes until well blended. This helps create a smooth base without needing a mixer.

2-Next, stir in the egg and vanilla extract until the mixture is even and glossy, making sure everything incorporates smoothly for the best texture.

3-In a separate bowl, sift together the flour, corn starch, salt, and baking soda to remove any lumps and ensure even distribution of leavening agents.

4-Gradually stir the dry ingredients into the wet mixture until fully combined, being careful not to overmix, which can lead to tough cookies.

5-Let the dough cool at room temperature for 10 minutes before folding in the chocolate chips. This step prevents the chips from melting too soon and keeps them intact.

6-Divide the dough into 12 portions for medium cookies or 24 for smaller ones, shape each into balls, and flatten them slightly for even baking.

7-Refrigerate the dough balls for 25 minutes to help them hold their shape at high altitudes and achieve that perfect chewy center.

8-Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper. Space the dough balls 2 inches apart on the sheet for proper spreading.

9-Bake on the center rack for 9-10 minutes for medium cookies or 6 1/2-7 minutes for small ones, until the edges are set but the centers are still a bit underdone for that soft finish.

10-Finally, cool the cookies on the baking sheet for 2 minutes before transferring to a wire rack to cool completely, allowing them to firm up just right.