Cook butter in a medium saucepan over medium heat, stirring often, until it foams and has a nutty aroma, about 5-7 minutes.
Transfer the butter to a heatproof bowl and allow to cool at room temperature for 30 minutes.
Using an electric mixer on medium speed, beat the cooled butter and sugars together, about 1 minute. Add eggs and vanilla, increase mixer speed to medium-high, and beat until mixture lightens and begins to thicken, about 1 minute. Scrape down the sides and bottom of the bowl as needed.
In a medium bowl, mix together the flour, cornstarch, baking soda and salt.
With the mixer on low speed, slowly mix in the dry ingredients into the wet ingredients until just combined. Add the chocolate chips and mix on low for about 5-10 seconds until combined. Cover with plastic wrap and place in the fridge for 30 minutes.
Preheat oven to 375°F and line baking sheets with parchment paper.
Scoop out 2 tbsp-sized portions and gently roll into a ball with your hands. Place 3 inches apart on the baking sheet.
Bake for 10-12 minutes, rotating the pan halfway through. You want the edges to be golden brown but the middle should still be soft. Sprinkle with some sea salt.
Allow the cookies to cool for 5 minutes on baking sheet before transferring to cooling rack.