In a large cup, combine ice cream and frozen whipped topping using a rubber spatula or a spoon. Stir in the butterscotch sauce, warmed peanut butter, and sea salt until no steaks remain.
Fold in the chopped Reese's. Place in freezer for 10-15 minutes until semi-frozen.
If you want to make ahead of time, prepare and freeze ice cream. Before serving, remove from freezer let defrost for 10 minutes, stir until smooth.