Prep the air fryer and cups. Preheat your air fryer to 325°F (160°C) for 3–5 minutes. Line your air fryer basket with silicone muffin cups or paper liners placed in a reusable muffin tray that fits the basket. Lightly spray the liners.
Mix the dry ingredients. In a large bowl, whisk flour, baking powder, baking soda, salt, pepper, garlic powder, onion powder, and Italian seasoning until evenly combined.
Whisk the wet ingredients. In a separate bowl or large measuring cup, whisk eggs, milk, yogurt, and olive oil until smooth.
Combine gently. Pour the wet mixture into the dry.
Stir with a spatula just until a few streaks of flour remain. Don’t overmix—this keeps the muffins tender.
Fold in the add-ins. Add cheddar, bacon (if using), spinach, bell pepper, and green onion. Fold until evenly distributed.
The batter will be thick and scoopable.
Fill the cups. Divide the batter into the liners, filling each about 3/4 full. If you like, sprinkle a little extra cheese on top for a golden crust.
Air fry in batches. Arrange the filled cups in the basket with space between them for airflow. Air fry at 325°F (160°C) for 12–16 minutes, until the tops are golden and a toothpick comes out clean or with a few moist crumbs.
Rest and release. Let muffins cool in the cups for 5 minutes, then remove to a rack.
This helps set the crumb and prevents sogginess.
Taste and adjust. Try one warm. If you want more punch next time, boost the salt, pepper, or cheese slightly.