Make the Pumpkin Donuts: In a large mixing bowl, whisk—or beat using an electric mixer—the oil, eggs, sugar, pumpkin and cinnamon. Stir in salt, baking powder and flour. Pour batter into a large resealable bag.
Spritz the wells of the donut maker with cooking spray or grease with a little vegetable/canola oil. Heat, and when it's ready to cook, snip a corner of the resealable bag. Use that to pour batter into each donut mold in the donut maker, filling them about two-thirds full. Close the lid and bake according to the machine's instructions, about 3 to 5 minutes per batch.
Use a fork to remove each batch of donuts, placing them on a cooling rack.
Make the Cinnamon Sugar: In a large resealable bag, combine cinnamon and sugar. As you're ready to serve the donuts (preferably still warm but not hot), toss a few in the bag, seal and shake to coat them. Only coat as many donuts as you plan on eating; otherwise, the coating will get moist and soggy. Store the donuts in a resealable bag at room temperature for up to 3 days.
