Rich Chocolate Chip Toffee Bars

2 ⅓ C. all purpose flour

⅔ C. packed light brown sugar

¾ C. butter or margarine

1 egg, slightly beaten

2 C. (12 oz.) chocolate chips, divided

1 C. coarsely chopped nuts, optional

1 can (14 oz.) sweetened condensed milk

1 ¾ C. toffee pieces, divided

Heat oven to 350º.  Grease 9x13 baking pan.  Combine flour and brown sugar in large bowl.  Cut in butter until mixture resembles coarse crumbs.  Add egg; mix well.  Stir in 1 ½ C. chocolate chips and nuts; set aside 1 ½ C. of the mixture.  Press remaining mixture in the bottom of greased pan.  Bake 10 min.  Pour sweetened condensed milk evenly over hot crust; top evenly with 1 ½ C. toffee bits.  Sprinkle reserved crumb mixture and remaining ½ C. chips over top.  Bake 25-30 min.  or until golden brown.  Sprinkle remaining ¼ C. toffee bits.  Cool completely in pan on wire rack.  Cut into bars.