Heat oven to 350°F.
Beat butter in bowl at medium speed, scraping bowl often, until creamy. Add flour, brown sugar, and salt; beat at low speed, scraping bowl often, until well mixed.
Press about 1 ¾ cups mixture onto bottom of lightly greased 13x9-inch baking pan with floured hands. Reserve remaining mixture. Bake 10-12 minutes or until edges are lightly browned.
Combine in small heavy saucepan 1 cup morsels and sweetened condensed milk. Cook over medium-low heat, stirring constantly, 3-5 minutes or until smooth. Spread over hot, partially baked crust.
Stir chopped nuts into remaining crumb mixture; sprinkle over bars. Drop scant teaspoonfuls of raspberry jam over chocolate and crumb mixture; sprinkle with remaining morsels. Bake 25-30 minutes or until topping is light golden brown and center is set.
Cool completely on wire rack. Cut into bars.
