Cream Unsalted Butter (1 1/3 cup), Granulated Sugar (1 cup), and Brown Sugar (1 1/2 cup) together in the bowl of a stand mixer fitted with the paddle attachment, until light and fluffy. Scrape the bowl, beat again on high for one minute. Add the Large Egg (2) and Pure Vanilla Extract (1 tablespoon) and beat until well blended, about another minute on medium-high speed.
Whisk Unbleached All-Purpose Flour (3 3/4 cup), Salt (1 1/2 teaspoon), and Baking Soda (1 teaspoon) together in separate bowl. Add to butter mixture and combine with a spatula or wooden spoon (or very briefly with paddle attachment) until just blended. Add the Semi-Sweet Chocolate Chips (12 ounce) and stir till combined. The dough will be stiff.
Portion into 1¾ oz (48 g) sized balls. This is a tedious task, but it makes for beautiful and uniform cookies that bake evenly. Chill the portioned balls for at least one hour, or keep in the fridge for weeks or freeze for months.
Preheat oven to 375 degrees F (190 degrees C).
Place portioned balls nicely spaced on an ungreased or parchment-lined jelly roll pan. Sprinkle with Sea Salt (to taste), if using. Bake for 11 minutes, rotating the sheet halfway through cooking. Keep a close watch.
You want to remove the cookies from the oven when they still look slightly raw—you will think you are removing them too early. The cookies will continue cooking as they sit on the tray out of the oven. Let cookies cool completely on tray before removing.