- 1 cup butter, softened
- 1 cup packed brown sugar
- 1 teaspoon vanilla extract
- 1 large egg yolk
- 2 cups all-purpose flour
- 1/4 teaspoon salt
- 2/3 cup milk chocolate chips
- 1/2 cup chopped walnuts
- Preheat oven to 350 degrees F (175 degrees C). Lightly grease a 9×13-inch baking dish.
- Beat butter, brown sugar, vanilla extract, and egg yolk in a large bowl; stir in flour and salt.
- Press dough into prepared baking dish.
- Bake in preheated oven until crust is light brown, 25 to 30 minutes.
- Immediately sprinkle chocolate chips over hot crust. Let stand until soft, about 5 minutes, and spread evenly; sprinkle with nuts.
- Cool pan on wire rack for 30 minutes.