Preheat your oven to 350°F (175°C) and grease a 24-cup mini muffin pan with nonstick spray.

In a mixing bowl, sift together all-purpose flour, baking powder, salt, ground nutmeg, and pumpkin pie spice.

In another bowl, mix pumpkin puree and brown sugar until combined. Stir in vegetable oil, vanilla extract, and egg, followed by milk.

Fold the dry ingredients into the wet mixture until just combined, creating a lumpy batter.

Fill each cup of the muffin pan about three-quarters full with batter.

Bake for 10 to 12 minutes, or until a toothpick comes out clean.

Let the donut holes cool in the pan for about 5 minutes.

Melt unsalted butter in a shallow bowl; combine sugar and cinnamon in another bowl.

Dip each donut hole in melted butter, then roll in the cinnamon-sugar mixture.

Serve warm with your favorite beverage.