Preheat the oven to 350°F with a rack in the center. Line a baking sheet with parchment or lightly grease. , In a medium bowl, vigorously beat together the brown sugar and butter until fluffy, about 1 minute. Beat in the egg yolk and vanilla until thoroughly combined. , Add the salt and baking soda to the bowl, stirring to fully incorporate. Weigh your flour; or measure it by gently spooning it into a cup, then sweeping off any excess. Add the flour to the bowl and stir until almost combined (a few streaks are OK).  , Add the chocolate chips and stir just until incorporated and no floury streaks remain. , Scoop the dough into generous 2-tablespoon portions (about 55g each); a jumbo cookie scoop is a helpful tool here. Place them, evenly spaced, on the prepared baking sheet.  , Bake the cookies for 12 to 14 minutes, or until the edges are just beginning to turn golden brown but the centers still look slightly underbaked. Cool cookies completely on the pan. , Store any leftover cookies in an airtight container at room temperature for several days.