Preheat oven to 350°F. Grease donut pan.
Mix dry ingredients: flour, sugar, baking powder, spices, and salt.
Whisk wet ingredients separately: pumpkin, eggs, oil, milk, and vanilla.
Combine wet and dry ingredients until just mixed.
Pipe batter into donut pan, filling ¾ full.
Bake 12-15 minutes until toothpick comes out clean.
Cool 5 minutes, remove from pan.
Mix cinnamon and sugar for coating.
Brush warm donuts with melted butter, roll in cinnamon sugar.