In a large mixing bowl, cream the butter and brown sugar until light and fluffy. Combine flour and salt; add to creamed mixture just until combined.

Press into a greased 15-in. x 10-in. x 1-in. baking pan. Bake at 350° for 10-12 minutes or until lightly browned.

Meanwhile, in a small saucepan, combine the butterscotch chips, corn syrup, butter and water. Cook and stir over medium heat until chips are butter are melted.

Spread over crust. Sprinkle with cashews; press down lightly. Bake for 11-13 minutes or until topping is bubbly and lightly browned. Cool on a wire rack. Cut into bars.