1-Preheat oven to 350 degrees: Preheat oven to 350 degrees. Line baking sheets with parchment paper. Whisk flour and baking soda together in medium bowl; set aside.
2-Heat butter in a skillet over medium-high: Heat butter in a skillet over medium-high heat until melted, about 2 minutes. Continue cooking, swirling pan constantly until butter is dark golden brown and has nutty aroma, 7 to 9 minutes. Remove from heat and let cool 5 minutes.
3-Add both sugars, salt, and vanilla to: Add both sugars, salt, and vanilla to bowl with butter and whisk until fully incorporated. Add egg and yolk and whisk until mixture is smooth with no lumps remaining, about 30 seconds. Let mixture stand 3 minutes, then whisk for 30 seconds. Repeat process of resting and whisking 2 more times until mixture is thick, smooth, and shiny. Using rubber spatula or wooden spoon, stir in flour mixture until just combined, about 1 minute. Mix in chocolate chips and ensure no flour pockets remain.
4-Divide dough into 64 equal portions or: Divide dough into 64 equal portions or about 0.6 ounces per cookie.
5-Bake cookies 1 tray at a time: Bake cookies 1 tray at a time until cookies are golden brown and still puffy, and edges have begun to set but centers are still soft, about 6 minutes. Transfer baking sheet to wire rack and let cookies cool completely before serving (if you can wait that long!)