In large bowl, combine bread and 1/4 C. water. Let stand for 5 minutes. Squeeze out excess water. Return bread to bowl, stir in beef, sausage, egg, Parmesan and parsley until well combined. Shape mixture into 16 balls. Using finger, make a hole in each meatball and insert a cube of mozzarella cheese. Shape meat around cheese and press to seal. In large skillet, heat 2 T. oil over medium heat. Add meatballs in batches, cook, turning until brown on all sides. (5-6 minutes) Drain on a paper towel. While meatballs brown, heat remaining 2 T. oil in a large pot over medium-high heat. Add onion and garlic. Cook, stirring often until lightly browned. Stir in marinara sauce and 1/4 C. water, bring to boil, reduce heat to a simmer. Add meatballs to sauce mixture, cover, bring to a boil. Reduce heat to medium-low and simmer until meatballs are cooked through, about 20 minutes. Meanwhile, cook spaghetti noodles according to directions and drain. Serve with meatballs and sauce. If you get tired of making the same old spaghetti, try this recipe, it takes a little time but is worth it!
