PREHEAT oven to 350° F. Grease 13 x 9-inch baking pan.
HEAT sugar and butter in medium, heavy-duty saucepan over low heat, stirring until butter is melted. Remove from heat. Add 1 1/4 cups morsels; stir until melted. Stir in eggs. Add flour, vanilla extract and baking soda; stir until flour is incorporated. Spread into prepared baking pan.
BAKE for 18 to 22 minutes or until wooden pick inserted in center comes out slightly sticky.
SPRINKLE with remaining morsels and nuts while still hot. Cover with foil; refrigerate until cooled completely.