1 large egg
1/2 cup milk
1 1/2 cups herb seasoned croutons
2/3 cup applesauce
3 Tablespoons chopped onion
3 Tablespoons minced garlic, or to taste
1/2 cup shredded Cheddar cheese (optional)
salt and black pepper to taste
1 1/2 pounds ground beef
1 (10.75-ounce) can condensed cream of celery soup
1/2 cup evaporated milk
1/4 cup grated Parmesan cheese (optional)
Preheat oven to 350ºF (175ºC).
Spray a 9x13 inch baking dish with cooking spray.
Whisk the egg and milk together in a large bowl, and stir in the croutons.
Allow the croutons to soak up the milk mixture for about 2 minutes.
Lightly stir in the applesauce, onion, garlic, Cheddar cheese, and salt and pepper, and mix in ground beef with your hands until thoroughly combined.
Form the meat mixture into 1 1/2-inch balls, and place into the prepared baking dish.
In the same bowl, whisk together the cream of celery soup with evaporated milk.
Pour the sauce over the meatballs.
Bake, uncovered, in the preheated oven until the sauce is bubbling and thickened and the meat is no longer pink in the middle, about 45 minutes.
Sprinkle with Parmesan cheese 15 minutes before end of baking, and bake until the cheese is melted and beginning to brown.
An instant-read thermometer inserted into the center of a meatball should read 160ºF (70ºC).