Mix all the ingredients for the crust in a bowl to combine well. Grease an 8x8 baking dish and press the crust ingredients onto the bottom of the baking dish.
Bake for 5 minutes and then allow to cool. In a blender, whip all the filling ingredients together and pour on to crust.
Freeze for 2 hours to set. In another blender, whip cream cheese, cool whip, and powdered sugar.
Spread topping onto the top of the set pumpkin. Sprinkle with butterscotch chips and pretzel. Refrigerate for 2 hours.