Preheat the oven. Heat the oven to 400°F. Line a baking sheet with parchment paper.
Mix the dry ingredients. Add the flour, baking powder, baking soda, salt, cinnamon, nutmeg, ground cloves and allspice to the bowl of a food processor fitted with a standard blade. Pulse 3 times.
Form the dough base. Add the butter and pulse 5-6 times, until a coarse meal forms. Scrape down the sides of the bowl and pulse an additional 3-4 times.
Mix the wet ingredients. In a small mixing bowl, whisk the pumpkin puree, heavy cream, egg, vanilla and brown sugar together.
Finish the dough. Drizzle the pumpkin mixture over the flour mixture and pulse 3-4 times. Scrape down the sides of the bowl and pulse an additional 4-5 times until a ball forms.
Prepare the scones. Sprinkle a bit of flour onto the parchment-lined baking sheet and transfer the dough ball to the baking sheet. Using lightly floured hands, press the ball into an 8" disk. Use a sharp knife to cut the disk into 8 equal-sized triangles (like pizza slices!)
Bake. Bake for 20 minutes and then remove the baking sheet from the oven and separate the wedges. Return to oven and bake for an additional 5-10 minutes until just golden brown at the edges.
Make the glaze. While the scones are baking mix the sugar, maple syrup, milk and vanilla in a small bowl. Set aside until ready to serve.
Serve. Remove the scones from the oven and let them cool for a few minutes. Drizzle with glaze and serve.