Preheat oven to 350℉. Grease a 9x13 baking dish with cooking spray. Set aside.
To a large skillet, add ground beef and onion and season with salt and pepper. Cook and crumble ground beef until no longer pink. Drain the grease, if needed, and return beef to skillet.
While the ground beef is cooking, add the soups, milk, Worcestershire sauce, garlic powder, Italian seasoning, and smoked paprika to a medium bowl. Whisk well to combine.
Pour soup mixture over ground beef and stir well to combine. Set aside.
Add a layer of potatoes to the bottom of prepared pan, followed by a layer of ground beef, and shredded cheese. Repeat with another layer, using the remaining ingredients, but do not top with cheese (that will come at the end of cooking so the cheese stays melty on top).
Cover with foil and bake for 1 hour to 1 hour 20 minutes, or until potatoes are fork tender. Remove foil, top with remaining shredded cheese, and bake (uncovered) for another 5-10 minutes, or until the cheese is melty. Let sit for 10 minutes before serving, as the casserole will thicken slightly.