Line 15x10x1-inch baking pan with foil, with ends of foil extending over sides of pan; grease foil. Set aside. Prepare dough as directed; spread into prepared pan. Bake 20 min. or until golden brown. Cool in pan. Lift dessert out of pan, using foil handles. Discard foil. Cut dessert into 36 bars. Store in tightly covered container at room temperature. Makes 3 dozen bars or 36 servings, 1 bar each.
Substitute 1-1/2 pkg. (12 squares) BAKER'S Semi-Sweet Baking Chocolate, chopped, for the semi-sweet chocolate chunks.