In a medium mixing bowl, combine breadcrumbs, egg, milk, parsley, Parmesan, Italian seasoning, onion powder, salt, and pepper. Stir until well mixed.

Add ground beef and turkey to the bowl. With clean hands or a fork, gently combine until just incorporated. Don’t overmix to avoid dense meatballs.

Form the mixture into 16 equal-sized meatballs, about 1 inch in diameter. Use a scoop or spoon for consistency.

Preheat your air fryer to 400°F, then lower it to 380°F right before cooking.

Place the meatballs in a single layer in the preheated air fryer basket. Avoid overcrowding to help them cook evenly.

Cook for 12-14 minutes. Use a meat thermometer to check that the internal temperature reaches 165°F.

Remove and rest the meatballs on a plate for 3 minutes before serving. This lets the juices redistribute.