In a large bowl, add the turkey, parsley, tomato paste, balsamic vinegar, garlic powder, oregano, sea salt, and black pepper and with your hands, combine well. With wet hands, roll the meat into 1½-inch meatballs.

In a 4- to 6-quart slow cooker, add the crushed tomatoes, diced tomatoes, Italian seasoning, balsamic vinegar, garlic powder, and sea salt. Stir to combine.

Place the meatballs into the slow cooker over marinara sauce.

Cover and cook on LOW for 8 hours or on HIGH for 4 hours. Serve the meatballs with the marinara sauce topped with parsley.