Preheat oven to 375°F. Lightly grease a 9x13-inch baking dish.
Boil macaroni in salted water until just shy of al dente. Drain and set aside.
Warm olive oil in a large skillet over medium-high heat. Brown ground beef, breaking it up. Drain excess fat.
Add onion and bell pepper to the skillet. Cook until tender, about 4 minutes. Stir in garlic for 30 seconds.
Stir in tomato sauce, diced tomatoes, Italian seasoning, paprika, salt, and pepper. Simmer 5 to 7 minutes.
Whisk cream cheese, sour cream, and milk in a bowl until smooth and creamy.
Toss drained pasta with the creamy mixture until evenly coated.
Layer half the creamy pasta in the dish. Spoon on half the meat sauce. Sprinkle with half the cheddar and mozzarella.
Repeat layers with remaining pasta and sauce. Top with remaining cheeses.
Mix breadcrumbs with melted butter. Scatter over the top.
Bake 20 to 25 minutes, until bubbling and golden. Rest 10 minutes, then garnish with parsley and serve.