Begin by tearing the white bread into small pieces and placing them in a bowl. Pour enough cold water over the bread to fully saturate it, letting it soak for about 5 minutes. Once softened, mash the bread with a fork until it forms a consistent mixture.

In a large mixing bowl, combine the soaked bread, ground beef, sweet Italian sausage, grated Parmesan, minced garlic, sea salt, black pepper, and the large egg. Gently blend the ingredients using your hands.

Shape the meat mixture into 1.5-inch balls and roll each meatball in all-purpose flour, shaking off any excess.

Heat a skillet over medium heat and add light olive oil. Place the meatballs into the skillet and cook them for about 6 minutes total, turning occasionally until golden brown.

In the same skillet, add the diced yellow onion and sauté for about 5 minutes until translucent, then add minced garlic and cook for an additional minute.

Add the crushed tomatoes and bay leaves to the onions, stir, and bring to a gentle boil. Let it bubble for about 5 minutes.

Return the browned meatballs to the skillet with the marinara sauce. Reduce heat to low and let them simmer uncovered for about 30 minutes.

While the meatballs simmer, bring a pot of salted water to a boil and cook the spaghetti according to package instructions until al dente, usually about 8-10 minutes.

Toss the drained spaghetti with the marinara sauce and meatballs, ensuring every strand is well-coated. Serve hot, garnished with extra Parmesan and fresh basil.