Preheat the Oven: Set your oven to 375°F to ensure even cooking.
Prepare the Meatloaf Base: In a large bowl, mix ground beef, bread crumbs, eggs, salt, and pepper. Press the mixture into the bottom of a baking dish.
Add the Macaroni and Cheese: Layer cooked macaroni noodles over the beef. Top with shredded cheddar cheese.
Make the Ketchup Sauce: In a separate bowl, mix milk and ketchup. Pour the sauce over the casserole.
Bake the Casserole: Place the dish in the oven and bake for 45 minutes, until the meatloaf is cooked and the top is golden.
Let It Cool: Allow the casserole to cool for a few minutes before serving.