1. Preheat oven to 350 degrees Fahrenheit (175 degrees Celsius).
2. Combine flour, sugar, butter, cinnamon, and salt in a bowl.
3. Press about half of the mixture into a sprayed 10-inch (26-centimeter) round or nine- x 13-inch (23- x 33-centimeter) pan.
4. Layer sliced apples on top.
5. Drizzle one-third cup cooled butterscotch sauce over the apples.
6. Crumble the rest of the dough into crumbs over the apples. Bake for 45 minutes to an hour.