In a medium bowl, mix together the flour, salt, baking soda, an cornstarch together. Set aside.

In your mixer, add the sugars and orange zest. Rub the zest and sugars between your fingers to combine and release the oils.

Add the butter to the mixer and beat until the mixture is light and fluffy.

Add the egg, egg yolk, and vanilla into the mixer and beat until well combined.

Pour the flour mixture into the mixer and mix until just combined and there are no streaks of flour. Fold in the chocolate chips.

Cover and chill the cookie dough for at least an hour, preferably overnight.

While the cookie dough is chilling, preheat the oven to 350 degrees F. Line two baking sheets with parchment paper.

Once the dough is finished chilling, portion out the cookie dough into balls that are 1 ½ tablespoons big.

Place the dough at least two inches apart and bake for 8 - 12 minutes, or until the are golden brown brown at the edges and puffy. The cookies should be slightly underbaked in the middle.

Allow the cookies to cool for two minutes on the baking sheet before transferring to a wire rack. While the cookies are still fresh from the oven, sprinkle salt over the cookies.