Prep the air fryer: Preheat to 325°F (165°C) for 3–5 minutes. This helps the muffins rise evenly.
Line your cups: Use silicone muffin cups or paper liners.
Lightly mist with oil if your liners stick.
Mix dry ingredients: In a large bowl, whisk flour, oats, baking powder, baking soda, salt, and cinnamon until well combined.
Mix wet ingredients: In another bowl, whisk maple syrup, yogurt, applesauce, oil, eggs, and vanilla until smooth.
Combine gently: Pour wet into dry. Stir with a spatula until just combined. Do not overmix. Fold in berries or other mix-ins.
Portion the batter: Fill muffin cups about 3/4 full.
This gives a nice dome without overflow.
Arrange in the basket: Place cups in a single layer with space between them for airflow. You may need to bake in batches.
Bake: Air fry at 325°F (165°C) for 10–12 minutes. Muffins are done when a toothpick comes out clean or with a few moist crumbs.
Cool: Let muffins rest in the cups for 5 minutes, then transfer to a rack to cool completely.
This sets the crumb and keeps them moist.
Serve: Enjoy warm as-is or with a smear of nut butter for extra protein and staying power.