Preheat oven to 375 degrees. Lightly dust a clean work surface with flour, and roll pastry dough into a 12-inch circle. Line an 8-inch pie plate with pastry, and trim pastry so it's even with edge of plate. Decorate edge with leaf shapes cut from excess pastry. Chill.
In a medium bowl, combine pumpkin puree, eggs, cream, sugar, allspice, cinnamon, ginger, and salt. Whisk until well blended. Pour into chilled pastry shell. Bake until crust is golden brown, and custard is set, 50 to 55 minutes. Let cool before serving.