01 - In a large mixing bowl, whisk together the flour, sugar, baking powder, baking soda, salt, and pumpkin pie spice until fully incorporated.
02 - In a separate bowl, blend the pumpkin puree, milk, egg, melted butter, and vanilla extract until smooth.
03 - Add the wet mixture to the dry ingredients and stir until just combined, avoiding overmixing.
04 - Lightly grease hands and roll portions of dough into 1-inch balls to yield approximately 20 pieces.
05 - Preheat the air fryer to 350°F for 3 minutes.
06 - Place the donut holes in a single layer in the air fryer basket, ensuring space between each for even cooking.
07 - Air fry for 7 to 8 minutes until golden brown and fully cooked, shaking the basket halfway through cooking.
08 - While warm, use a pastry brush to coat donut holes with melted butter.
09 - Combine granulated sugar and ground cinnamon, then toss the buttered donut holes in the mixture until evenly coated.
10 - Arrange donut holes on a serving platter and enjoy warm.