01 -
In a large bowl, combine ground beef, breadcrumbs, Parmesan cheese, egg, finely chopped onion, garlic powder, salt, and pepper until well incorporated.
02 -
Shape the meat mixture into evenly sized meatballs, approximately 1-1/2 inches in diameter.
03 -
Place the formed meatballs in a single layer in the crockpot.
04 -
In a separate bowl, whisk together beef broth and French onion soup mix until combined, then pour evenly over the meatballs.
05 -
Cover and cook on low heat for 6-8 hours or high heat for 3-4 hours, until meatballs are thoroughly cooked.
06 -
Sprinkle mozzarella cheese evenly over the meatballs and continue cooking for an additional 15 minutes until cheese is completely melted.