Make the marinara sauce (see the link for the recipe in the Ingredients list)

Process the bread in a food processor until coarsely ground. Add the rest of the ingredients and pulse until finely ground. Set aside.

Tear the bread into pieces and place it in a bowl. Add the milk and let it sit for a few minutes to fully absorb. Set aside.

In a large mixing bowl, use your hands to mix together the beef, pork, and eggs. Now add the Italian breadcrumbs, parsley, basil, salt, garlic, and pepper. Mix well.

Squeeze the milk-soaked bread and add to the meat mixture. Add the Parmesan cheese, and mix until fully combined.

Cover the bowl with plastic wrap and place it in the fridge for about 15 to 20 minutes.

Remove the meat mixture from the refrigerator. Fill a small bowl with water and have it near the meat mixture. Line a baking sheet with parchment paper (or wax paper). Wet your hands and pull enough of the meat mixture to form a ball with your hands slightly larger than a golf ball, approx. 3 oz. Place the ball on the parchment paper-lined baking sheet and continue with the remaining meat mixture. You should yield about 15 to 17 meatballs. Cover with plastic wrap and place in the refrigerator for at least 1 hour, preferably 2, or longer.

Heat the olive oil (2 tbsp) in a non-stick skillet over medium-high heat. When the oil is shimmering, and working in batches, add 3 or 4 meatballs and cook them for about 10 minutes, carefully turning them frequently until they are browned on all sides. Use a couple of forks or spoons to help maintain a spherical shape as they brown. Transfer to a platter and continue until all balls have been browned. Set aside. (They will still be pink in the center - they will finish cooking while simmering in the marina.)

Meanwhile, in a large pot, heat the marina over medium heat.

Slowly, and carefully, add the meatballs and any accumulated juices to the marina. Simmer for 45 minutes to 2 hours. Watch the pan, gently stir often, and don't let the bottom of the pan burn!

Bring a large pot of salted water to a boil, and cook the spaghetti until al dente, about 10 - 11 minutes.

Reserve about a cup of the pasta water, and then drain the pasta.

Heat a large, heavy skillet over medium-high heat, add about a cup of the sauce.

Add the cooked pasta, and incorporate the sauce so it coats the pasta. Add a little of the pasta water to loosen the pasta.

Add more sauce, stir, and add more pasta water if needed. Transfer to a serving platter. Add meatballs to the top, and pass with extra sauce.

Top with grated Parmesan cheese and chopped parsley, if desired. Serve at once.