Preheat the oven to 350 F or 180 C and grease a doughnut tray with melted butter, oil or non-stick spray. If you don't have a doughnut tray, no worries! You can make the same recipe in a muffin tray (you can also place a ball of foil in the middle of the doughnut tray to make little doughnuts!).
In a bowl, combine the oil, pumpkin puree, eggs, sugar, cinnamon, nutmeg, ginger, vanilla, salt and baking powder. Mix till smooth.
Stir in the flour.
Using a spoon, fill the doughnut trays with about ¼ cup of batter per cup (for the bigger doughnuts- about 3 inches in diameter). It doesn't matter how large the doughnut cups are- just make sure they are full about ¾ of the way!
Bake the doughnuts for 15 minutes (about 10 for the smaller ones).
Let them cool for about 5 minutes.
Gently loosen the doughnuts from the moulds by nudging them with a knife.
Place the cinnamon sugar in a ziplock bag (I actually like to use a little more than ¼ cup and then save the excess for another recipe).
Add the doughnuts to the ziplock bag one at a time. Seal the bag and shake to coat the doughnuts with the sugar.
Gently remove the doughnut from the bag and let it sit on a cooling rack.
Enjoy with a nice cup of tea.
These store nicely in a sealed container in the fridge for about a week (though I like to eat them at room temp/slightly warmed).