Preheat the oven to 350 and grease a 6-count donut pan with cooking spray.
Add pumpkin puree, eggs, and almond milk to a mixing bowl and whisk together until smooth. Mix in almond flour, coconut flour, pumpkin pie spice, Erythritol, and baking powder until everything is combined.
Transfer your donut batter into a quart sized zip top bag or pastry bag and cut a large opening in one of the corners. Squeeze the batter evenly into the prepared donut molds.
Bake the donuts for 14-16 minutes. Remove from the oven and let cool while you prepare the cinnamon sugar coating.
In a small mixing bowl, melt the butter and set aside.
In a separate bowl, mix together Erythritol, cinnamon, and pumpkin pie spice.
While the donuts are still warm, carefully remove them from the molds. Dip both sides of the donut in butter and then coat in the cinnamon/erythritol mixture and set on a wire rack to cool.