Position oven rack to lowest position. Preheat oven to 425°. To prepare filling, combine first 6 ingredients in a large bowl, stirring with a whisk. Add pumpkin, and stir with a whisk until smooth.
To prepare crust, roll dough into an 11-inch circle; fit into a 9-inch pie plate coated with cooking spray. Fold edges under and flute. Pour pumpkin mixture into the crust. Place pie plate on a baking sheet. Place baking sheet on lowest oven rack. Bake at 425° for 10 minutes. Reduce oven temperature to 350° ( do not remove pie from oven); bake an additional 50 minutes or until almost set. Cool completely on wire rack. Serve with dollop of low fat whipped topping.