Spinach Garlic Meatballs Stuffed With Mozzarella

Name: Spinach Garlic Meatballs Stuffed With Mozzarella
Cuisine: European, Italian, Mediterranean
Ingredients: 8 ounces baby spinach, fresh; 3 cloves garlic, finely chopped; 1-2 T. olive oil; 1 pound ground beef; 1 pound ground pork; 2¼ c. bread crumbs; 3 eggs; splash of milk; 4 garlic cloves, finely chopped; ½ c. Parmesan; salt/pepper; 2 T. olive oil; mozzarella cheese (cut into small cubes); 1 jar Rao's marinara sauce