Preheat oven to 325°F. In small bowl, combine flour, baking soda, and salt; set aside. In small saucepan, combine butter, sugar, and water; bring just to a boil. Remove from heat. Add half of chips and vanilla. Stir until morsels melt and mixture is smooth. Transfer to large bowl. Add eggs one at a time, beating well after each addition. Gradually blend in flour mixture. Stir in remaining chips and nuts. Spread into greased 9-inch square baking pan. Bake at 325°F.
Time: 30-35 minutes. Cool completely. Cut into 16 2¼-inch squares.