Preheat your oven to 375°F (190°C). Bring a large pot of salted water to a boil. Cook the elbow macaroni according to package directions until al dente (usually 7-8 minutes). Drain and set aside.

While the pasta cooks, heat oil in a large skillet over medium-high heat. Add the diced onion and cook for 3-4 minutes until softened. Add the ground beef, breaking it up with a spoon. Cook until no pink remains, about 5-7 minutes. In the last minute, add the minced garlic, Worcestershire sauce, paprika, salt, and pepper. Stir to combine. Drain any excess fat.

Reduce the heat to low. To the skillet with the beef, add the undiluted cream of mushroom soup, sour cream, and milk. Stir until smooth and fully combined with the beef mixture. Heat through for 2-3 minutes, but do not boil.

Remove the skillet from heat. Stir in the drained cooked pasta and 1 cup of the shredded cheddar cheese. Mix until everything is evenly coated in the creamy sauce.

Transfer the mixture to a greased 2-quart (or 9x13 inch) casserole dish. Spread evenly. Sprinkle the remaining 1/2 cup of cheddar cheese over the top. If using, mix the breadcrumbs with melted butter and sprinkle over the cheese.

Bake in the preheated oven for 20-25 minutes, or until the top is golden brown and the edges are bubbling.

Let the hotdish rest for 5-10 minutes after removing it from the oven. This allows it to set for cleaner scooping. Garnish with chopped parsley if desired, then scoop generous portions directly from the casserole dish to serve.