In a large mixing bowl, combine the ground beef, Italian breadcrumbs, grated Parmesan cheese, beaten egg, minced garlic, onion powder, dried oregano, salt, and black pepper. Use your hands or a fork to gently mix everything together until just combined. Avoid overworking the meat, as this can lead to tough meatballs.
Scoop about 1.5 to 2 tablespoons of the mixture and roll it between your palms to form a smooth ball, roughly the size of a golf ball. Repeat this process until all the mixture is used, aiming for about 16 to 20 meatballs of uniform size for even cooking.
Preheat your air fryer to 400°F (200°C) for about 3 to 5 minutes. Once heated, lightly spray the air fryer basket with olive oil spray to prevent the meat from sticking.
Place the meatballs in the air fryer basket in a single layer, ensuring they are not touching so the air can circulate freely. Lightly spray the tops of the meatballs with olive oil spray. Air fry at 400°F (200°C) for 10 to 12 minutes.
Halfway through the cooking time (around the 6-minute mark), gently shake the basket or use tongs to turn the meatballs. This ensures they brown evenly on all sides. Once they reach an internal temperature of 160°F (71°C) and look golden brown, remove them from the air fryer and let them rest for 2 minutes before serving.