Preheat the oven to 350 degrees F (175 degrees C). Lightly grease a 9x13-inch baking dish.

Beat butter, brown sugar, vanilla, and egg yolk together in a large bowl until well combined; stir in flour and salt until incorporated. Press dough into the prepared baking dish.

Bake in the preheated oven until crust is light brown, 25 to 30 minutes.

Remove from the oven and immediately sprinkle chocolate chips over hot crust. Let stand until soft, about 5 minutes, then spread evenly; sprinkle with nuts. Cool on a wire rack for at least 30 minutes before slicing.