Preheat the oven to 375 degrees F and grease two 6-cup donut pans with nonstick spray.

Add the pumpkin, milk, butter, egg, and vanilla to a large bowl. Whisk to combine well.

Add the flour, sugar, pumpkin pie spice, baking powder, baking soda, and salt to the bowl. Whisk to combine into a thick batter.

Use ¼ cup batter in each prepared donut spot.

Bake for 12-14 minutes, or until puffed up, golden brown, and a cake tester or toothpick inserted into the center of a donut comes out clean.

Remove from oven and let cool for a minute or so. Run a knife around the edges to loosen, as needed, then transfer donuts to a wire rack to cool completely.

Optional: Stir the sugar and cinnamon together in a small bowl. Dip the top of each donut first in the melted butter, then in the cinnamon-spice mixture.