Preheat the oven to 375°F. Line a baking tray with parchment paper.
In a large bowl, whisk together flour, sugar, baking powder, salt, and 2 teaspoons of pumpkin pie spice. Add cubed cold butter. Use a pastry cutter or two forks to cut the butter into the flour mixture, until the texture resembles coarse crumbs.
In a separate bowl, combine the pumpkin puree, 6 Tablespoons heavy cream, beaten egg, and 1 teaspoon vanilla. Gradually add the pumpkin mixture to the flour mixture, stirring with a fork until just combined, and a rough dough forms. If the dough seems too dry, add an extra Tablespoon of cream.
Lightly sprinkle the work surface with flour and turn out the dough onto the surface. Knead gently until it comes together. Flatten the dough into a 1 inch thick rectangle or circle and cut into 12 wedges (I love using a bench scraper). Place scone wedges onto prepared baking tray and refrigerate for 30 minutes.
After chilling, brush the tops of the scones with remaining 1 Tablespoon of heavy cream and sprinkle with the remaining ½ teaspoon pumpkin pie spice.
Bake for 25 minutes, or until the tops are golden brown and the scones reach an internal temperature of 200°F. Let cool for 5 minutes on the baking tray, then transfer to a wire rack to cool completely.
Drizzle glaze over cool scones and let set for about 10 minutes before serving.
Notes
Keep leftovers in an airtight container at room temperature for 2 days and in the freezer for 3 months.