Heat oven to 350°F. Place pie crust in 9-inch glass pie plate as directed on box for One-Crust Filled Pie.
In medium bowl, mix brown sugar and flour with wire whisk. Add butter, eggs, vanilla and salt; mix well. Stir in butterscotch chips. Pour into crust-lined plate.
Bake 40 to 42 minutes or until top is browned and filling is set. Cool completely before slicing, about 3 hours.