PLACE chocolate squares and butter in large microwavable bowl.
Microwave on high 2 minutes or until butter is melted.
Stir until chocolate is completely melted.
Add sugar; stir until well blended.
Mix in eggs.
Add flour; mix well.
Stir in nuts.
Spread into 13x9 inch baking pan lined with greased aluminum foil.
BAKE at 350° F (325° F for glass dish) for 30-35 minutes or until toothpick inserted in center comes out with fudgy crumbs
DO NOT OVERBAKE!
While brownies are in oven, place caramels and milk in microwavable bowl.
Microwave on high 2-1/2 minutes, stirring after 1 minute.
Stir until caramels are completely melted and mixture is well blended.
Gently spread over baked brownies in pan.
Sprinkle with chocolate chunks.
Cool in pan on wire rack.
Lift out of pan onto cutting board.
Cut into squares.
Cool. Cut into bars.