1. Preheat oven to 350°. Fit piecrust into a 9-inch pie plate according to package directions; fold edges under, and crimp.
2. Whisk together brown sugar and next 4 ingre-dients in a large bowl until smooth. Whisk in melted butter. Stir in pecans and butterscotch morsels. Pour mixture into piecrust.
3. Bake at 350° for 50 minutes or until set and slightly puffed. Cool completely on a wire rack (about 4 hours).