Preheat oven to 350°F. Cook egg noodles according to package directions until al dente. Drain and set aside.
In a large skillet over medium-high heat, brown ground beef with diced onion until beef is no longer pink, about 8-10 minutes. Drain excess fat.
Add minced garlic and cook for 1 minute until fragrant. Stir in tomato sauce, diced tomatoes, Italian seasoning, salt, and pepper. Simmer for 5 minutes.
In a separate bowl, mix together cream cheese, sour cream, and 1 cup of mozzarella cheese until well combined.
In a greased 9x13-inch baking dish, layer half the cooked noodles, then spread the cream cheese mixture over them, then add remaining noodles.
Pour the beef and tomato mixture over the top and spread evenly. Sprinkle with remaining 1 cup mozzarella cheese.
Bake uncovered for 25-30 minutes until cheese is melted and bubbly. Let stand 5 minutes, garnish with fresh parsley if desired, and serve.