Preheat the oven to 350°F and grease a 24-cup mini-muffin pan with cooking spay or softened butter.
Whisk the flour, baking powder, baking soda, salt, and spices in a medium-sized bowl.
Place the oil, granulated sugar, brown sugar, and vanilla in a large bowl. Whisk to combine.
Add the eggs and yolk, one at a time, and continue whisking until smooth. Add the pumpkin and whisk again.
Add the dry ingredients to the wet, and using a rubber spatula, gently fold to combine. Do not over mix.
Evenly fill each cavity in the mini muffin tin with a tablespoon and a half of batter.
Bake for about 10 to 12 minutes, rotating the pan at the halfway mark, until a toothpick inserted in the center of one of the donuts in the center of the pan comes out clean.
While the donuts bake, make the cinnamon sugar coating. Whisk the sugar and cinnamon together in a small bowl with some depth. Place the melted butter in another small bowl.
Once the donut holes have cooled enough to handle, but are still quite warm, remove them from the pan and begin dipping them one at a time in the bowl of butter and then rolling them in the cinnamon sugar.
Transfer the coated holes to a wire rack. Serve immediately.
The donuts are best eaten the day they are made, but will last a day, or so, on the counter wrapped in plastic wrap. They also freeze beautifully: once they are at room temperature, place them into the freezer on a cookie sheet. Once frozen, transfer them to zippered plastic bag and keep in the freezer for up to a month. Let them come to room temp before serving.