Preheat oven to 350° F. In large mixing bowl, beat peanut butter and butter until smooth, about 1 minute. Add sugar, eggs and vanilla, and beat until creamy. Blend in flour and salt. Stir in 1 cup of the chocolate chips. Spread into ungreased 13x9 inch baking pan. Bake 25-30 minutes, or until edges begin to brown. Immediately sprinkle remaining morsels over cookie layer. Let stand 5 minutes until morsels become shiny and soft. Spread the rest of the chocolate chips evenly over top. Cool completely.