Make the Crust: In a large bowl, whisk together the flour and salt. Cut in the butter and shortening using a pastry blender or your fingers until the mixture resembles coarse crumbs. Gradually add the ice water, one tablespoon at a time, mixing until the dough just comes together. Form the dough into a disc, wrap in plastic wrap, and refrigerate for at least 30 minutes.

Prebake the Crust: On a lightly floured surface, roll out the dough into a 12-inch circle. Transfer to a 9-inch pie plate. Trim and crimp the edges. Preheat oven to 375°F (190°C). Line the crust with parchment paper and fill with pie weights or dried beans. Bake for 15 minutes. Remove the parchment paper and weights, and bake for another 5-10 minutes, or until lightly golden. Let cool completely.

Prepare the Filling: In a large bowl, whisk together the pumpkin puree, eggs, brown sugar, heavy cream, milk, cinnamon, ginger, cloves, nutmeg, and salt until smooth.

Bake the Pie: Pour the filling into the prebaked crust. Reduce oven temperature to 350°F (175°C). Bake for 50-60 minutes, or until the filling is set around the edges but still slightly wobbly in the center. If the crust starts to brown too quickly, cover the edges with foil.

Cool and Serve: Let the pie cool completely on a wire rack before refrigerating for at least 4 hours, or preferably overnight. Serve chilled, with whipped cream if desired.