In a large bowl, whisk together flour, salt, and sugar. Add the cold cubed butter and use a pastry cutter or your fingertips to work it into the flour until the mixture resembles coarse crumbs with some pea-sized pieces remaining.
Drizzle ice water, one tablespoon at a time, mixing gently after each addition until the dough just begins to come together. Form the dough into a disk, wrap in plastic, and refrigerate for at least 1 hour or up to 2 days.
Preheat your oven to 375°F (190°C). On a lightly floured surface, roll the chilled dough into a 12-inch circle. Transfer the dough to a 9-inch pie dish.
Gently press the dough into the dish, trim any excess leaving a 1-inch overhang, then fold and crimp the edges decoratively.
Line the crust with parchment paper and fill with pie weights or dried beans. Bake for 15 minutes, then carefully remove the weights and parchment.
Prick the bottom of the crust with a fork and bake for an additional 5 minutes until just beginning to color. Remove from oven and reduce temperature to 350°F (175°C).
In a large bowl, whisk together pumpkin puree, brown sugar, salt, and spices until well combined.
In a separate bowl, lightly beat the eggs, then whisk in the heavy cream and vanilla. Gradually incorporate the egg mixture into the pumpkin mixture, whisking until completely smooth and silky.
Pour the filling into the par-baked crust. If the crust edges are browning too quickly, shield them with a pie crust protector or strips of aluminum foil.
Bake at 350°F (175°C) for 50-55 minutes, or until the center is almost set but still slightly wobbly – it should jiggle like Jell-O but not be liquid.
Allow the pie to cool completely on a wire rack for at least 2 hours before slicing. For the cleanest cuts, refrigerate for 1-2 hours after cooling to room temperature.