In a large bowl, combine the ground beef, Italian sausage, Italian seasoning, parsley, Parmesan cheese, eggs, and bread crumbs. Mix until just combined.

Using a medium cookie scoop, scoop out 24 meatballs. Using your hands shape the meat mixture into golf ball-sized meatballs.

In the bowl of a slow cooker, stir together all the sauce ingredients until well combined.

Gently add the meatballs to the sauce in the slow cooker, making sure they are completely covered by the sauce

Cover and cook on low for 8 - 10 hours. After 4 hours, gently stir the sauce to blend, being careful not to break up the meatballs. Replace lid back on and finish cooking.

Serve hot as is, over pasta, or in sub rolls covered with cheese and toasted in the oven.