Preheat oven to 350°F and spray 2 donut pans with baking spray.
In the bowl of your stand mixer fitted with the paddle attachment, beat together oil, eggs, sugar, pumpkin, pumpkin pie spice, salt, and baking powder.
With a spoon, add in flour and mix together until no lumps remain.
Scoop the batter into a pastry bag or large Ziploc bag and cut off the tip. Pipe batter into donut pans about 3/4 full.
Place in oven for 16-18 minutes or until a toothpick comes out clean in the center. Mine took the full 18 minutes.* Let donuts cool on a wire rack.
Pumpkin Spice Sugar
In a large ziploc bag, combine pumpkin spice and sugar. Shake. Add in hot donuts, one at a time, and shake bag until donuts are completely covered. Let cool on a wire rack.
In the bowl of a stand mixer fitted with a paddle attachment, combine butter, sugar, salt, and vanilla. Beat on low slowly adding each tablespoon of milk. If frosting is too thick, continue adding milk, 1 tablespoon at a time, until the desired consistency is reached.
Dip cooled donuts into frosting and set on a wire rack. Top with sprinkles, if desired. Allow frosting to harden for at least 30 minutes before eating. Enjoy!
*If making muffins, allow bake time to be 25 minutes.