Beat butter in large bowl until creamy add in flour sugar and salt until crumbly with floured fingers press 2 cups of crumb mixture onto bottom of greased 13x9 pan bake for 10 to 12 minutes in 350F oven warm 1 1/2 cup morsels and milk in small pan stirring until smooth add in vanilla spread over hot crust add walnuts and remaining morsels into crumb mixture sprinkle over chocolate filing bake in 350F oven for 25-30 minutes