Unroll the pie crust and press into a 9" pie plate. Set aside.
Cream butter and sugar with a mixer for about 3 minutes. Add eggs, evaporated milk, vanilla, sweet potatoes and spices and beat well. Pour into prepared pie crust.
Bake for 15 minutes at 425. Reduce oven temperature to 350 and continue to bake for 30-35 minutes or until center is set and crust edges are browned. Remove from oven and cool completely before refrigerating.
Remove from the refrigerator and serve topped with whipped topping.