1 cup + 2 tbsp. all-purpose flour
½ tsp. baking soda
½ tsp. kosher salt
1 tsp. vanilla extract
½ cup (1 stick) unsalted butter, at room temperature
½ cup firmly packed light brown sugar
½ cup granulated sugar
1 cup semisweet chocolate chips or chunks
Stir together the flour, baking soda, and kosher salt in a small bowl. Set aside.
Stir together the egg and vanilla in a small bowl. In the bowl of a stand mixer fitted with the paddle attachment, beat the butter, brown sugar, and granulated sugar on medium speed until just mixed, about 20 seconds. Scrape down the sides of the bowl.
Add the egg mixture to the butter mixture and beat well, about 10 seconds. Reduce the speed to low, slowly add the dry ingredients, and beat until just incorporated. Stir in the chocolate chips.
Position the rack in the center of the oven and preheat to 375 degrees. Line 2 baking sheets with parchment paper.
Drop rounded tablespoonfuls of dough 2 inches apart onto the prepared baking sheets. Bake until the cookies are golden brown, 10 to 12 minutes (they will seem underdone). Let the cookies cool on the baking sheets for 2-3 minutes, then transfer the cookies to wire racks and let cool completely.