Heat oven to 350. Grease a 9 x 13” pan. Combine flour, sugar and salt; cut in ½ cup butter. Press into prepared pan. Bake at 350 for 10 minutes. Combine butterscotch chips, corn syrup, 2 T butter and water in a medium saucepan; heat and stir over medium heat until mixture is smooth. (I usually just do this in the microwave!) Spread mixture over crust and top with nuts. Bake at 350 for 10 minutes or until bars are bubbling. Cool slightly; cut into bars.