1. Preheat the oven to 375°F and lightly grease a 9×13-inch baking dish.

2. Cook the egg noodles in salted boiling water until al dente, then drain well.

3. Brown the ground beef in a large skillet over medium-high heat, breaking it apart as it cooks. Drain excess grease if needed.

4. Add the chopped onion and cook for 3 to 4 minutes, until softened.

5. Stir in the garlic and cook for 30 seconds, until fragrant.

6. Add the marinara sauce, diced tomatoes, Italian seasoning, paprika, salt, and black pepper. Simmer for 5 minutes.

7. In a large bowl, mix the softened cream cheese and sour cream until smooth.

8. Add the cooked noodles to the cream cheese mixture and stir gently until coated.

9. Spread half of the creamy noodles into the prepared baking dish, then spoon half of the beef sauce over the top.

10. Repeat with the remaining noodles and beef sauce.

11. Sprinkle cheddar cheese and mozzarella cheese evenly over the casserole.

12. Bake for 20 to 25 minutes, until hot, bubbly, and lightly golden on top.

13. Let the casserole rest for 5 to 10 minutes, then garnish with sliced green onions and serve.