Preheat oven to 350 degrees and spray a doughnut pan with baking spray.
Using a standing mixer, beat the vegetable oil, pumpkin puree, and sugar and add in eggs, one at a time, until well combined and smooth.
In a medium bowl, combine the flour, pumpkin pie spice, salt, and baking powder until combined.
Gradually mix in the dry ingredients into the wet.
Pour batter into the donut pan about 3/4 way full.
Bake in the oven for 15 to 18 minutes or until a toothpick inserted into the center of one comes out clean.
Remove from oven and allow to cool for 5 minutes.
Place 1 cup of sugar and 1 tsp cinnamon into a large Ziplock bag.
Add a few doughnuts into the bag and shake until donuts are covered in sugar.
Remove from bag and place onto a wire rack to cool.