This recipe is based off Cook's Illustrated Perfect Chocolate Chip Cookies recipe.
Ingredients 1¾ cups all-purpose flour ½ teaspoon baking soda 14 tablespoons unsalted butter, divided ¾ cup dark brown sugar ½ cup granulated sugar 1 teaspoon salt 2 teaspoons vanilla extract 1 egg 1 egg yolk 1¼ cups semisweet chocolate chips
Directions Preheat oven to 375 degrees F. Line 2 large (18x12-inch) baking sheets with parchment paper. In a medium bowl, whisk together the flour and baking soda; set aside.
Heat 10 tablespoons of the butter in a 10-inch stainless steel or cast iron skillet over medium-high heat until melted, about 2 minutes. Continue cooking, swirling the pan constantly until the butter is dark golden brown and has a nutty aroma, 1 to 3 minutes. Remove skillet from heat and transfer the browned butter to a large heatproof bowl. Stir the remaining 4 tablespoons butter into the hot browned butter until completely melted. Set aside and let cool to room temperature.
Add both sugars, salt, and vanilla to the bowl with the butter and whisk until fully incorporated. Add the egg and egg yolk and whisk until the mixture is smooth with no sugar lumps remaining, about 30 seconds. Let the mixture stand for 3 minutes, then whisk for 30 seconds. Repeat the process of resting and whisking 2 more times until the mixture is thick, smooth, and shiny. Using a rubber spatula or wooden spoon, stir in the flour mixture until just combined, about 1 minute. Stir in the chocolate chips and give the dough a final stir to ensure there are no hidden flour pockets.
Scoop the dough into 16 even portions, each about 3 tablespoons, and arrange them 2 inches apart on the prepared baking sheets, 8 dough balls per sheet. Bake the cookies 1 tray at a time until the cookies are golden brown but still puffy, and the edges have begun to set but centers are still soft, 10 to 14 minutes, rotating the baking sheet halfway through baking. Transfer the baking sheet to wire rack and allow cookies to cool completely before serving. Cookies can be stored in an airtight container at room temperature for up to 3 days. It is recommended that you use weight measurements for the best results. You can use light brown sugar instead of dark, but the characteristic butterscotch/toffee flavor will be less pronounced.