Whisk together the flour, sugar, baking powder, pumpkin pie spice, and salt in a large bowl; set aside.

In a separate bowl, combine the pumpkin puree, heavy cream, and beaten egg until smooth and thick.

Grate the cold butter into the dry mixture, then work it in with your fingers or a pastry cutter until coarse crumbs form.

Pour the pumpkin mixture into the flour-butter bowl and knead gently by hand just until a soft, sticky dough forms.

Fold the dough over on itself 6 to 7 times, shape it into a 6-inch disc, wrap tightly in plastic wrap, and refrigerate for at least 30 minutes.

Preheat the oven to 400 degrees F and line a half sheet pan with parchment paper or a silicone mat.

Roll the chilled disc into a 10-inch circle about 1/2 to 3/4 inch thick, then cut it into 12 wedges with a bench scraper or sharp knife.

Arrange the wedges on the prepared pan with about 1/4 inch of space between them so they can lean on each other as they bake.

Bake for 20 to 25 minutes until puffed and golden brown, then cool on the pan for 5 minutes.

Beat the cream cheese, powdered sugar, cinnamon, and salt with a hand mixer on low speed until smooth, then increase to high speed and whip for 2 to 3 minutes until light and fluffy.

The glaze should hold soft ribbons from the beaters when ready; set it aside until the scones are baked.

Transfer the scones to a wire rack and spoon or spread the glaze over them while still warm for a thin drizzle, or wait until fully cool for a thicker frosting-like finish.