Microwave butter for about 30 seconds so it’s barely melted. If needed, microwave for an additional 10 seconds. Butter should be liquified but not sizzling.
Beat the butter with the sugars until creamy, using a stand mixer or hand-held beaters on medium speed for 2 minutes. It should look like caramel. Add vanilla and egg, then beat again on low speed for about 10 seconds.
Add flour, baking soda, and salt. Mix only a couple of rotations until crumbles form, about 30 seconds. Add chocolate chips and use your hands to knead them into the cookie dough.
Roll dough into 20 medium sized balls about 2 inches across and place on a cookie sheet lined with parchment paper. Bake for 12 minutes until the cookies look puffy and just barely golden. They will sink a little as they cool but stay soft and delicious.