1. Soak the bread crumbs in the milk in a large bowl for 5 minutes. Add the ground beef, parsley, onion powder, garlic powder, basil, oregano, salt, pepper, Parmigiano-reggiano cheese, and egg. Mix to combine. Cut mozzarella cheese into ½-inch cubes

2. Divide into 2 tablespoon size meatballs. Add a cube of mozzarella in the center of each meatball and shape into a ball. Repeat with remaining mozzarella cheese and meat.

3. Heat olive oil in a large saucepan over medium heat. Add onion and sauté for 5 minutes. Add garlic and cook another 30 seconds. Add tomatoes, basil, oregano, and salt and pepper. Simmer over low heat for 15 minutes, stirring occasionally.

4. Add the meatballs to the sauce. Simmer and cook, turning the meatballs partway if they aren't completely covered in sauce, until the meatballs are cooked through.

5. Meanwhile, cook the spaghetti noodles in a large pot of salted, boiling water according to package directions until al dente (typically around 8-10 minutes).

6. Drain and toss the spaghetti with the meatballs and sauce, then sprinkle with additional Parmigiano-Reggiano cheese and chopped parsley to serve.