Preheat Oven: Preheat the oven to 350°F (175°C). Grease a 9×13-inch baking dish.
Prepare Sauce: In a medium mixing bowl, combine 1 cup ketchup and 1 cup barbecue sauce. Set aside.
Make Meatloaf Base: In a large mixing bowl, combine ground beef, crushed Ritz Crackers, Lipton onion soup mix, eggs, and 1/2 cup of the ketchup-barbecue mixture. Mix thoroughly and press evenly into the prepared baking dish. Spread remaining ketchup-barbecue mixture on top. Bake for 30 minutes.
Cook Macaroni: While meatloaf is baking, cook macaroni noodles according to package directions and drain.
Prepare Mac and Cheese: In a large bowl, whisk together milk and condensed cheddar cheese soup until smooth. Add salt, pepper, garlic powder, and onion powder. Stir in cooked macaroni and 2 cups of shredded cheese.
Assemble Casserole: Remove meatloaf from oven. Pour macaroni mixture on top of meatloaf and spread evenly. Sprinkle remaining 2 cups shredded cheese on top.
Bake Again: Bake for an additional 17–20 minutes, until the cheese is melted and slightly browned. Let rest for a few minutes before serving.
