"Line 8-inch square pan with foil, with ends of foil extending over sides; spray with cooking spray. Combine flour, baking soda and salt. Mix egg, sugar, butter and vanilla in large bowl until blended. Add dry ingredients; stir just until blended. Stir in chocolate chunks and nuts.,Pour into prepared pan.,Bake 22 to 24 min. or until toothpick inserted in the center comes out clean. Cool completely. Use foil handles to remove dessert from pan before cutting into bars...."