Whisk the oat flour, almond flour, baking powder, cinnamon, ginger, nutmeg, and salt together in a large bowl. Grate in the frozen butter and work it in with a pastry cutter, a fork, or your fingers until the mixture comes together in pea-sized crumbs. Set aside.

In a small bowl, whisk together the milk, egg, pumpkin, and brown sugar. Drizzle it over the flour mixture and then mix it all together until everything is combined. The dough may be wet.

Using floured hands, and adding a little more oat flour if necessary, form the dough into a ball and then gently press it into a flat disk about 1 inch thick. Place the dough on a parchment-lined plate and place it in the fridge for at least 30 minutes and up to 1 hour.

Remove the chilled dough from the fridge and cut it into 8 equal pieces. Place the scones about 2 inches apart on the baking sheet, then place in the oven and bake for 25 minutes.

Remove the scones and let them cool on a wire rack.

Whisk together the melted butter, maple syrup, powdered sugar, and a big pinch of salt. Drizzle the glaze over the scones.