Preheat your oven to 400°F and line a large baking sheet with parchment paper.
In a food processor, pulse the flour, baking powder, baking soda, salt, cinnamon, and pumpkin pie spice until well combined.
Add the butter and pulse several times until no large pieces remain. Transfer the mixture to a large mixing bowl. (If you're mixing by hand, whisk the dry ingredients in a large bowl, then use a pastry cutter to blend in the butter).
In a small bowl, whisk together 1/3 cup heavy cream, egg, blotted pumpkin, brown sugar, and vanilla extract.
Drizzle over the flour mixture and mix until everything is evenly moistened.
Place a large piece of parchment paper on your work surface and lightly flour it. With floured hands, shape the dough into a ball and transfer it onto the floured parchment. Press into a smooth 8-inch disc, then slice into 8 equal wedges with a sharp knife.
Arrange the scones at least 2 inches apart on the prepared baking sheet. Brush the tops with the remaining heavy cream using a pastry brush.
Bake the scones for 12–15 minutes, or until lightly golden and a toothpick inserted into the center comes out clean. Transfer to a wire rack and let cool for 10 minutes before adding the glaze.