In a large bowl, mix together the ground beef, egg, bread crumbs, garlic powder, onion powder, kosher salt, pepper, Worcestershire sauce and yellow mustard. Using a cookie scoop, portion out the meatballs and set on a plate. Roll to ensure they are round.
Spray your air fryer with nonstick spray. Preheat at 400 degrees if your air fryer requires it. Place meatballs in a single layer in the air fryer, making sure they do not touch. Cook at 400 degrees F for 10 minutes. Cook in batches if needed.