Heat oven to 350°F (325°F for dark or nonstick pan). Grease bottom only of 13x9-inch pan with shortening or cooking spray. In medium bowl, stir brownie mix, pouch of chocolate syrup, oil, water and eggs until well blended. Spread in pan. In small bowl, combine nuts and chocolate chips; sprinkle half of mixture over batter in pan. Set remaining nut mixture aside.