Combine the ground meat, egg, breadcrumbs, Parmesan, minced garlic, parsley, Italian seasoning, kosher salt, and black pepper in a bowl. Mix only until the ingredients are combined, then shape the mixture into approximately 18–20 small meatballs, about 1 1/2 inches (4 cm) each.

Place the diced bacon in a large skillet or Dutch oven over medium heat. Cook for 5–7 minutes, until browned and most of the fat has rendered, then transfer the bacon to a plate and leave about 1–2 tablespoons of fat in the pan.

Add the meatballs to the bacon fat, working in batches if necessary so they have room to brown. Cook for about 5–7 minutes total, turning them onto several sides, then remove them from the pan; they do not need to be fully cooked yet.

Add the chopped onion to the same pan and cook for 3–4 minutes, stirring until softened. Add the minced garlic and cook for about 30 seconds, then stir in the crushed tomatoes, diced tomatoes, oregano, and cooked bacon, seasoning lightly because the bacon and Parmesan already contain salt.

Return the browned meatballs to the tomato sauce and partially cover the pan. Simmer gently for 15–20 minutes, turning the meatballs once or twice, until they are cooked through and reach 160°F (71°C) in the center.

Meanwhile, bring a large pot of well-salted water to a boil and cook the pasta according to the package timing until al dente. Before draining, reserve at least 1/2 cup of the pasta water, then drain the noodles.

Toss the drained pasta with some of the tomato sauce, adding a small splash of reserved pasta water if the sauce seems thick. Serve the pasta with the meatballs, bacon, optional fresh herbs, and grated Parmesan.