Combine the first 3 ingredients and 1 tablespoon of sugar in a bowl; cut in the butter with a pastry blender until the mixture resembles a coarse meal and is pale yellow (about 3½ minutes). Sprinkle with ice water, 1 tablespoon at a time, over the surface; toss with a fork until the flour is moistened and the mixture is crumbly (do not form a ball.) Add more flour, if needed - if it appears to be too sticky.
Gently press the mixture into a 4-inch circle on a sheet of heavy-duty plastic wrap, and cover it with another sheet of plastic wrap; chill 15 minutes.
Roll the dough, still covered, into a 13-inch circle; place it in the freezer for 5 minutes or until the wrap can be removed easily. Remove the bottom sheet. Fit the dough into a 9-inch pie plate coated with cooking spray; remove the top sheet. Fold the edges under and flute; set aside. *Don't let the dough sit in the freezer too long or it will "break" when you try to fit it into the plate.
FILLING
Preheat the oven to 350°F.
Combine the filling ingredients in a large mixing bowl; use an electric mixer to beat at medium-speed until well blended. Pour the filling into the pastry shell.
Bake for 1 hour or until a knife inserted into the center comes out clean. Cool on a wire rack.
Slice and serve with a dollop of fresh whipped cream or vanilla ice cream.
Notes
You can use a refrigerated pie crust for this recipe (or your favorite homemade crust), though it will change the nutritional information.