Preheat the oven to 400 degrees. Line a large cast iron skillet with foil and set aside.
In a large mixing bowl combine ground beef, ground pork, Italian breadcrumbs, whole milk, minced garlic, Italian seasonings, onion powder, dried parsley, Parmesan cheese, salt, pepper, and lightly beaten eggs. Using your hands mix all ingredients in the bowl until just combined, being careful not to over mix the meat.
Use an ice cream scoop to form meatballs. You should be able to make 17 large meatballs from the meat mixture (or 34 smaller ones).
Place meatballs on the foil lined cast iron skillet and place in the oven. Cook at 400 degrees for 25 minutes (20 minutes if smaller meatballs). Remove from the oven and set the cast iron skillet on a hot pad.
Lower the oven temperature to 375 degrees. Place meatballs on a plate and remove foil from cast iron skillet.
Pour ½ of the pasta sauce on the bottom of the skillet. Add meatballs back to the skillet on top of the pasta sauce.
Pour remaining sauce over the top of the meatballs. Add 1 - 1 ½ cups shredded mozzarella cheese to the top of the meatballs. Sprinkle on Italian seasonings.