Roll out pie dough on a lightly floured surface to a 12-inch circle. Transfer to a 9-inch pie dish, pressing gently into the bottom and sides. Trim and crimp the edges, then freeze for 15 minutes while you heat the oven.

Heat oven to 375°F. Line the frozen crust with parchment and fill with pie weights or dried beans. Bake on a baking sheet until the edges are set and just starting to turn golden, 15 to 18 minutes. Remove weights and parchment, then bake 5 minutes more until the bottom looks dry. Set aside to cool slightly. Reduce oven to 325°F.

In a large bowl, whisk the mascarpone until smooth and loosened, about 30 seconds. Add the heavy cream and whisk until fully combined and no lumps remain.

Whisk in the pumpkin puree, brown sugar, eggs, vanilla, cinnamon, ginger, nutmeg, and salt until the filling is completely smooth and homogeneous. For the silkiest texture, pass the mixture through a fine-mesh sieve into a clean bowl.

Pour the filling into the warm par-baked crust. Bake at 325°F until the edges are set but the center still jiggles slightly when you nudge the pan, 45 to 55 minutes. The filling should register 165°F on an instant-read thermometer.

Transfer to a wire rack and cool completely, at least 3 hours or up to overnight. The pie will continue to set as it cools. Serve at room temperature or chilled, with lightly sweetened whipped cream if desired.