Preheat the oven to 350ºF and spray a donut pan with nonstick cooking spray.
Combine the dry ingredients together in a medium bowl and set aside.
Using an electric mixer or stand mixer, cream the butter, brown sugar, and vanilla together until the mixture is light in color. Add the maple syrup, pumpkin puree, and almond milk to the mixing bowl and mix until combined.
Add one egg at a time to the bowl and mix until combined.
Slowly add the dry ingredients to the wet ingredients until the batter is a muffin or cake batter consistency.
Transfer the donut batter to a piping bag or large gallon sized bag. Snip the end of the bag and pipe the donut batter into the donut pan, filling each donut ¾ of the way full.
Bake at 350ºF for 8-10 minutes or until the donuts are fully cooked.
Remove the pan from the oven and let the donuts cool for a few minutes before carefully removing each donut from the pan and placing them on a cooling rack.
While the donuts are cooling, add the white sugar and cinnamon into a small bowl and mix until combined.
When the donuts are cooled, use a pastry brush to carefully brush all sides of the donuts with melted butter and then immediately roll or toss the donuts in the cinnamon sugar mixture until the donut is completely coated. Be sure the whole donut is covered. Place the donut back onto the cooling rack. Repeat until every donut has been coated.