Preheat oven to 400°. On a lightly floured surface, roll dough to a 1/8-in.-thick circle; transfer to a 9-in. pie plate. Trim crust to 1/2 in. beyond rim of plate; flute edge.
In a small bowl, combine sugar, cornstarch, salt and cinnamon. In a large bowl, combine eggs, pumpkin and sugar mixture. Gradually stir in milk. Pour into crust.
Bake for 10 minutes. Reduce heat to 350°; bake until a knife inserted in the center comes out clean, 45-50 minutes. Cool on a wire rack. If desired, serve with whipped cream. Refrigerate leftovers.