Best Big, Fat, Chewy Chocolate Chip Cookie

Gather all ingredients. Preheat the oven to 325 degrees F (165 degrees C). Grease cookie sheets or line with parchment paper.

Sift flour, baking soda, and salt together; set aside.

Beat brown sugar, melted butter, and white sugar with an electric mixer in a large bowl until smooth.

Beat in egg, egg yolk, and vanilla until light and creamy; add flour mixture and stir until dough is just combined.

Stir in chocolate chips.

Drop spoonfuls of dough 3 inches apart onto the prepared baking sheets.

Bake cookies in the preheated oven until edges are golden, about 15 to 17 minutes.

Cool on the cookie sheets briefly before transferring them to a wire rack to cool completely.