Preheat the oven to 350 degrees. Lightly grease the pans. Beat together the vegetable oil, eggs, sugar, pumpkin puree, pumpkin pie spice, salt and baking powder until smooth. Add the flour, stirring until smooth. Fill the pans 3/4 full. Bake 15-18 minutes. Allow the donuts to cool in the pans for a few minutes before transferring to a drying rack. In a small bowl, combine the powdered sugar, water and vanilla extract until smooth. Dip the top of the donut in the glaze mixture and add any sprinkles or toppings that you desire. Serve and enjoy!