In a large mixing bowl, combine ground beef, ground pork, fresh breadcrumbs, grated Parmesan cheese, shredded mozzarella, eggs, minced garlic, finely chopped onion, chopped parsley, dried oregano, salt, pepper, and whole milk. Mix gently until just combined.

Roll the meat mixture into golf ball-sized meatballs, about 24 pieces. Place them on a baking sheet lined with parchment paper.

Heat olive oil in a large skillet over medium heat. Brown the meatballs for 2-3 minutes on each side until golden-brown. Remove from skillet.

In the same skillet, add more olive oil if needed, and sauté minced garlic until fragrant, about 30 seconds.

Add canned crushed tomatoes, dried basil, dried oregano, crushed red pepper flakes, and sugar to the sautéed garlic. Season with salt and pepper. Let the sauce simmer for 5 minutes.

Return browned meatballs to the sauce, cover, and let them simmer on low for 20-25 minutes.

Remove from heat and garnish with fresh basil leaves. Serve with pasta, bread, or creamy polenta.