Place your pie pastry into the bottom of a 9 inch pie plate and set aside.
In a large mixing bowl, mix together the sweet potato and melted butter. Add in the sugars, cream, flour, vanilla extract, and pumpkin pie spice. Beat until combined, then taste test. Add more spice if needed.;
Add in the eggs and then beat on medium speed until the mixture is smooth.
Pour the filling into the prepared pie plate.
Bake in the preheated oven for 55-65 minutes, until a knife inserted into the center comes out clean.