In a large bowl, combine flour, brown sugar, baking powder, pumpkin spice, cinnamon, and salt until fully mixed.

Cut the cold butter into the mixture using a pastry cutter, two forks, or a food processor until it forms a crumbly texture, with butter chunks no larger than peas.

Stir in the pumpkin puree, buttermilk, and vanilla extract gently until the mixture is evenly moistened, being careful not to over-mix.

Turn the dough onto a lightly floured surface, folding it a few times until it forms a cohesive ball. Flatten it into an 8-inch circle.

Using a sharp knife or bench scraper, cut the dough into 8 wedges, wiping your knife if needed.

Place the wedges on a parchment-lined baking sheet, spacing them 2 inches apart. Transfer the tray to the freezer for 10-15 minutes while preheating the oven to 425°F.

Brush the tops of the scones with buttermilk, then bake for 13-15 minutes or until they are golden and fully baked. Let them cool on a wire rack.

For the glaze, whisk powdered sugar, buttermilk, and vanilla together until smooth. Drizzle the glaze over the cooled scones and enjoy!