Preheat oven to 400. Line 1 or 2 large baking sheets with parchment paper or silicone baking mat(s). Set aside.
Make the scones: Whisk the flour, baking powder, cinnamon, pumpkin pie spice, and salt together in a large bowl. Cut the butter into small pieces and add to the flour mixture. Combine it with a pastry cutter, a fork, or your fingers until the mixture comes together in pea-sized crumbs. Set aside.
Whisk 1/3 C heavy cream, the egg, pumpkin, brown sugar, and vanilla together in a small bowl. Drizzle it over the flour mixture and then mix it all together until everything appears moistened.
With floured hands, work the dough into a ball as best you can and transfer onto a floured work surface. Press into a neat 8-inch disc and, with a very sharp knife, cut into 8 equal wedges.
Place scones at least 2 inches apart on the prepared baking sheet(s). Using a pastry brush, brush scones with remaining heavy cream.
Bake for 18-20 minutes or until lightly browned. Remove from the oven and allow to cool for a few minutes as you prepare the icing.
Make the glaze: In a small saucepan over low heat, melt the butter and maple syrup together, whisking occasionally. Once the butter has melted, remove from heat and whisk in the sifted confectioners' sugar. Taste and add a pinch of salt if desired. Drizzle over warm scones.