Preheat oven to 375F. Roll pastry out to fit a 9-inch pie pan and transfer to pan leaving about 1 inch of overhang. Fold edges under and crimp edges. Chill pie crust in refrigerator or freezer while preparing the filling.
In a large bowl, whisk pumpkin puree, sugars, eggs, milk, heavy cream, pumpkin pie spice, cornstarch, vanilla, and salt until smooth. Pour pumpkin filling into prepared crust.
Bake pumpkin pie at 350F 65-75 minutes until center of pie is almost set (cover the crust edges with a pie shield or tin foil if they are browning too fast) The very center of the pie will still be a little wobbly when the pie is done – this is okay. Remove pie from oven and transfer to a cooling rack to cool completely.
Once pie is cooled, refrigerate at least 2 hours before serving. Slice pie into wedges and serve with whipped cream. Enjoy!