If making homemade crust, whisk together flour and salt in a large bowl. Cut in cold butter using a pastry cutter or two knives until mixture resembles coarse crumbs.
Gradually add ice water, one tablespoon at a time, mixing gently until dough holds together when pinched. Form into a disk, wrap in plastic, and refrigerate for 30 minutes.
Preheat oven to 375°F (190°C). Roll chilled dough on a floured surface into a 12-inch circle. Transfer to a 9-inch pie dish, trim excess leaving a 1-inch overhang, then fold and crimp edges.
Line crust with parchment paper and fill with pie weights or dried beans. Bake for 15 minutes, then remove weights and parchment and bake for another 5 minutes until very light golden.
In a large bowl, whisk brown sugar and eggs until well combined and slightly lightened in color. Add pumpkin puree, heavy cream, spices, salt, and vanilla extract. Whisk until completely smooth and no streaks remain.
Pour filling into the par-baked crust. Cover crust edges with foil or a pie shield to prevent over-browning.
Bake at 375°F for 50-55 minutes, or until the center jiggles slightly but edges are set (similar to how a cheesecake looks when done). The filling should reach an internal temperature of 175°F for perfect doneness.
Place pie on a wire rack and cool completely to room temperature (at least 2 hours). For best results and cleanest slices, refrigerate for at least 1 hour after cooling.
Serve with optional toppings as desired.