Combine flours, salt, and sugar in a bowl. Cut in the butter using a pastry cutter, fork, or simply your hands. Mix and crumble together until the mixture resembles coarse meal. Add ice water 1 Tbsp at a time, tossing and stirring with a fork until it just holds together. Wrap in plastic wrap and let rest in fridge at least 1/2 hour. Remove and let warm up a bit about 5 minutes before you plan to roll it out.
When ready to bake, heat oven to 425° F.
Place pumpkin, cream, eggs, spices, vanilla, and salt in a food processor or blender and process until smooth. In a small bowl whisk the sugars and cornstarch together until there are no lumps. Add to pumpkin mixture and whisk until everything is smooth.
Roll out crust and fit into a 9-inch pie pan.
Pour filling into crust and bake at 425 for 15 minutes; then lower temperature to 350° F and bake until the filling is puffed and just set, about 50-60 minutes, lightly covering the top of the pie with aluminum foil if the crust starts to brown too much. Cool completely, at least 2 hours, and serve at room temperature or cold.