1. Reduce the Apple Cider: Start by simmering the apple cider in a small saucepan over medium heat until it’s reduced to about 1/4 cup. This concentrates the flavor and should take about 20 minutes. Let it cool.

2. Mix Dry Ingredients: In a large bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, and nutmeg.

3. Combine Wet Ingredients: In another bowl, whisk the melted butter, sugar, eggs, vanilla extract, buttermilk, and the reduced apple cider.

4. Combine Wet and Dry Mixtures: Add the wet ingredients to the dry ingredients and stir until just combined. Be careful not to overmix.

5. Prepare the Air Fryer: Preheat your air fryer to 360°F. If your model requires preheating, follow the manufacturer’s instructions.

6. Shape Donut Holes: Using a small scoop or spoon, form the batter into balls. You can lightly grease your hands with oil to prevent sticking.

7. Cook: Place the donut holes in the air fryer basket, making sure they are not touching. Cook for about 4 minutes, then flip each donut hole and cook for an additional 4 minutes.

8. Coat the Donut Holes: Mix sugar and cinnamon in a shallow bowl. While the donut holes are still warm, toss them in the cinnamon sugar to coat evenly.