In a large bowl, whisk together flour, sugar, baking powder, baking soda, and salt.
In a separate bowl, whisk together sour cream, milk, eggs, and butter.
Add the wet ingredients to the dry and mix with a spoon or spatula until just combined. The batter will be lumpy. Don't overmix. Let batter rest while you prepare the pan and preheat air fryer.
Spray donut pan with cooking oil to help prevent the donut from sticking. Preheat air fryer for a few minutes.
Spoon batter into each donut pan cavity until about 3/4 full. Bake in air fryer at 320°F/160°C for 7-9 minutes, until lightly golden brown. Let cool in pan for about 5 minutes, then remove.
Serve warm with your favorite pancake toppings!
Notes
Baking time may vary depending on the size of the donuts and your air fryer.