Make the crust by pulsing gluten free flour, sugar, and salt in a food processor. Add cold butter and pulse until pea-sized crumbles form. Drizzle in ice water and pulse until dough holds together. Press into a 9-inch pie dish and build up the edges. Refrigerate for 30 minutes.
Preheat oven to 375F. Line the chilled crust with parchment paper, fill with pie weights or dried beans, and blind bake for 15 minutes. Remove weights and parchment and bake 5 minutes more. Reduce oven temperature to 350F.
In a large bowl, whisk together pumpkin puree, brown sugar, pumpkin pie spice, and salt. Add eggs one at a time, whisking well after each. Stir in heavy cream and vanilla extract until smooth.
Pour the filling into the pre-baked crust. Bake for 45 to 50 minutes until the edges are set but the center has a slight jiggle when gently shaken.
Let cool completely on a wire rack, then refrigerate for at least 4 hours or overnight before slicing. Serve with whipped cream.