Chill the cookie dough for at least 4 hours or overnight.

In a medium bowl, whisk together the flour, cornstarch, baking powder, baking soda, and salt. Set aside.

In a large mixing bowl, beat the butter and sugars on medium-high speed until pale and fluffy.

Scrape down the bowl and add the eggs and vanilla. Beat on medium-high speed for about 3 minutes until pale and creamy.

Scrape down the bowl and mix again.

Add the dry ingredients and mix on low-medium speed until almost combined.

Fold in the chocolate using a rubber spatula. Do not over mix.

Weigh out each cookie to be 6 oz or shape into 3/4 cup portions. Place the dough balls on a tray and press extra chocolate chips on top if desired.

Chill the dough uncovered for at least 4 hours or preferably overnight.

Preheat the oven to 350F and place 3 cookies on a large baking sheet lined with parchment paper.

Bake for 13-16 minutes, until the edges are pale golden and the center looks dull but doughy.

After removing the tray, gently tap it against the counter to flatten the cookies. Use a fork to adjust any edges.

Sprinkle the warm cookies with sea salt and let them settle for 3-5 minutes.

Transfer to a cooling rack and continue baking the remaining cookies.