Preheat the oven to 350°F (175°C) and lightly grease a 9-by-13-inch baking dish to prevent sticking.
Bring a large pot of salted water to a boil. Add the noodles and cook until just al dente. Drain well and set aside.
Warm olive oil in a large skillet over medium heat. Add the chopped onion and cook until it becomes soft and translucent. Stir in the minced garlic and sauté briefly until fragrant, about 30 seconds.
Add the ground beef to the skillet, breaking it apart as it cooks. Continue browning until fully cooked through, then drain any excess grease from the pan.
Incorporate the tomato sauce or crushed tomatoes into the beef. Season with oregano, salt, black pepper, and paprika if using. Let the mixture simmer gently for 5 to 7 minutes to allow the flavors to meld.
In a separate bowl, mix the softened cream cheese with the sour cream until smooth. Fold in the cooked noodles, stirring to coat them evenly in the creamy mixture.
Transfer the noodle mixture into the prepared baking dish, spreading it out in an even layer. Spoon the beef and tomato mixture over the noodles. Sprinkle the shredded cheddar cheese evenly over the top.
Place the casserole in the oven and bake uncovered for 25 to 30 minutes, or until the cheese is melted and bubbling at the edges.
Allow the casserole to rest for 5 minutes after baking before serving. Optionally, garnish with freshly chopped parsley for added freshness.