Spray the wells of a mini donut pan with cooking spray and set it aside.
In a mixing bowl, beat the oil, eggs, sugar, pumpkin, cinnamon, ginger, cloves, salt and baking powder until the mixture is smooth. Beat in the flour just until it’s all incorporated.
Transfer the batter to a piping bag or a large zip-top plastic bag with the tip snipped off.
Fill each well on the pan about three-fourths full, and bake for 10 to 12 minutes.
Remove the donuts from the pan and let them cool.
In another zip-top bag, combine the sugar and cinnamon.
Lightly brush each donut with melted butter, and then drop them (a few at a time) into the bag, and gently shake to coat them in cinnamon-sugar. Serve immediately, and store any leftovers in an airtight container.