Preheat oven to 425°F.
Roll out the pie crust dough into a large circle and place it into a 9" deep-dish pie plate, cutting away any excess crust.
Flute or crimp edges (if desired) and place in refrigerator.
In a large bowl combine the pumpkin puree, sweetened condensed milk, eggs, pumpkin pie spice, cinnamon, and salt. Whisk until smooth.
Pour the pumpkin mixture into the crust. Bake for 15 minutes.
After 15 minutes, keeping the oven door closed, reduce the temperature to 350°F and bake 35-40 more minutes, or until a knife inserted comes out clean.
Transfer the pie to a cooling rack. Let the pie come to room temperature before cutting and serving.
Serve cold with whipped topping.