Preheat the oven to 350°F and grease the donut pans, unless you're using silicone donut pans.
Mix together the milk and vinegar in a small bowl and let sit for at least 5 minutes.
1/2 cup whole milk, 1 teaspoon apple cider vinegar
Stir together all of the dry ingredients for the donuts.
1 cup all-purpose flour, 1/2 cup brown sugar, 1 teaspoon baking powder, 1/2 teaspoon baking soda, 1 teaspoon ground cinnamon, 1/2 teaspoon ground ginger, 1/4 teaspoon ground cloves, 1/4 teaspoon salt
Add in all of the wet donut ingredients and stir well.
1/2 cup pumpkin puree, 2 Tablespoons vegetable oil, 1 teaspoon vanilla extract
Pour, or spoon, about ¼ cup of the batter into each donut cavity. The batter should fill the donut cavities about ⅔ of the way up; if it doesn’t, adjust it until it does.
Bake the donuts for about 13 minutes, using a toothpick to check when they are done. Allow the donuts to cool for at least 10 minutes on a wire rack before topping them.
Make the topping by whipping together the cinnamon and sugar.
Once the donuts are cool, dip them in the melted butter, then cover the donuts in the cinnamon and sugar mixture by dipping, rolling, or sprinkling the mixture over the donuts.
1/4 cup salted butter, 1/2 cup granulated sugar, 1 Tablespoon ground cinnamon