Preheat the oven to 350°F and grease a 6-count donut pan with cooking spray.
In a medium bowl, whisk together the dry ingredients. Set aside.
In a bowl of a stand mixer fitted with the whisk attachment (or with handheld electric beaters), beat the coconut oil and brown sugar for 1-2 minutes or until creamy.
Add the maple syrup, vanilla, pumpkin puree, oat milk, egg and cashew butter. Beat for 2 minutes, scraping the bowl down as needed.
Add the dry ingredients to the wet ingredients and mix on medium speed for 1-2 minutes until well combined. Scrape down the sides of the bowl and mix again.
Transfer the batter to a large piping bag and cut off the end (or place into a gallon ziplock bag). Pipe half of the batter into the donut pan cavities.
Bake for 15-18 minutes or until a toothpick inserted into the center comes out clean.
While the donuts bake, mix together the cinnamon-sugar mixture in a medium shallow bowl.
Transfer the pan of baked donut pan to a wire cooling rack and let cool for 5 minutes before turning the pan over to remove the donuts from the pan. Let donuts cool for 8-10 minutes. When donuts are still a bit warm, dip them into the cinnamon-sugar mixture until evenly coated. Let cool completely.
Fill the now-empty baking pan with the remaining batter and bake as directed above. Repeat with cooling & cinnamon-sugar steps as directed above.