In a large bowl, combine ground beef, ground pork, soaked breadcrumbs (breadcrumbs mixed with milk), egg, Parmesan, garlic, parsley, salt, and pepper. Mix until well combined but do not overwork.

Form meatballs

Shape the mixture into 1.5-inch meatballs and place on a tray.

Brown meatballs

Heat olive oil in a large skillet over medium-high heat. Brown the meatballs in batches, turning to brown all sides. Do not cook through. Set browned meatballs aside.

Make Meat Sauce

Sauté aromatics

In a large saucepan, heat olive oil over medium heat. Add chopped onion and sauté for 5 minutes until soft. Add garlic and cook for an additional minute.

Simmer sauce

Add crushed tomatoes, tomato paste, oregano, basil, salt, pepper, sugar, and water or broth. Stir to combine.

Add meatballs

Gently place browned meatballs into the sauce. Reduce heat to low, cover, and simmer for 30 minutes, stirring occasionally.

Cook Pasta and Serve

Boil pasta

Bring a large pot of salted water to a boil. Add spaghetti and cook according to package directions until al dente. Drain.

Assemble and serve

Serve spaghetti topped with meat sauce and meatballs. Garnish with grated Parmesan cheese.