Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
In a large mixing bowl, whisk together the sifted flour, sugar, baking powder, cinnamon, nutmeg, and salt.
Cut the cold butter into small cubes and add to the flour mixture. Using a pastry cutter or your fingertips, cut in the butter until the mixture resembles coarse crumbs.
Stir in the pumpkin puree and maple syrup until just combined; the dough will be slightly shaggy but hold together.
In a small bowl, whisk the egg and then add it to the dough, mixing gently until the dough comes together.
Turn the dough out onto a lightly floured surface and gently knead it a few times to shape into a disc about 1 inch thick.
Cut the disc into 8 wedges using a sharp knife or bench scraper. Place the wedges on the prepared baking sheet, spaced evenly apart.
Bake the scones in the preheated oven for about 15 minutes, or until the tops are golden brown and they sound hollow when tapped.
While the scones bake, prepare the glaze by whisking together powdered sugar, milk, and vanilla extract until smooth and thick.
Once baked, remove the scones from the oven and let them cool slightly on a rack for about 5 minutes.
Drizzle the warm scones with the maple glaze, allowing it to set slightly before serving.
Serve the pumpkin scones warm or at room temperature, enjoying their flaky texture and flavorful spice aroma.