Add the entire box of spice cake mix to a large mixing bowl.
Pour in the 15 ounces of pumpkin puree. Do not add eggs, oil, or water. The pumpkin replaces those ingredients.
Mix thoroughly until fully combined and smooth. Scrape down the sides of the bowl to ensure no dry cake mix remains. The batter will be thick.
Line silicone or paper muffin liners that fit inside your air fryer basket. Fill each liner about ¾ full to allow room for rising.
Place the filled muffin liners into the air fryer basket in a single layer.
Air fry at 320°F (160°C) for 10 to 14 minutes, depending on your air fryer model and liner size.
Check doneness by inserting a toothpick into the center. If it comes out clean, the muffins are ready. If not, cook for 1–2 more minutes.
Remove carefully and allow the muffins to cool for at least 5 minutes before serving.