In a large bowl combine pumpkin puree, sweetened condensed milk, eggs, and pumpkin pie spice. Mix with a hand mixer or mix very well with a spoon.
Pour mixture into pie crust.
Bake for 10 minutes, then reduce heat on the oven to 350 and continue baking the pie for 35 minutes. Turn off heat and let the pie sit in the oven for 5 minutes, then remove from the oven (the pie filling will have puffed up, it will slowly settle back down) and allow to cool completely (2 hours-overnight). I like to make the pie the day before and let it sit overnight in the refrigerator.
I like to serve my pumpkin pie with a dollop of whip cream and I sprinkle a little pumpkin pie spice over the whipped cream.