Classic Cookies

Adjust oven rack to middle position. Preheat oven to 375º F. Line 2 large (18- by 12-inch) baking sheets with parchment paper. Whisk flour and baking soda together in medium bowl; set aside.

Heat 10 tablespoons butter in 10-inch 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, 1 to 3 minutes. Remove skillet from heat; transfer browned butter to large heatproof bowl. Add remaining 4 tablespoons butter into hot butter stirring until completely melted.

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 sugar 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 a rubber spatula or wooden spoon, stir in flour mixture until just combined, about 1 minute. Stir in chocolate chips and nuts (optional), giving dough final stir to ensure no flour pockets remain.

Divide dough into 16 portions, each about 3 tablespoons (or use #24 cookie scoop). Arrange 2 inches apart on prepared baking sheets, 8 dough balls per sheet. (Smaller baking sheets can be used, but will require 3 batches. )