Preheat your oven to 375°F (190°C).

In a large bowl, mix ground beef, breadcrumbs, milk, egg, onion, garlic, Worcestershire sauce, salt, and pepper until well combined.

Press the meat mixture into a greased 9x9-inch baking dish, forming an even layer.

Spread ketchup over the top of the meatloaf layer.

Bake in the preheated oven for 25 minutes.

Meanwhile, cook macaroni according to package instructions. Drain and set aside.

In a saucepan, melt butter over medium heat. Stir in flour and cook for 1 minute.

Slowly whisk in the warm milk. Cook, stirring constantly, until the sauce thickens.

Add shredded cheddar cheese. Stir until melted and smooth. Season with salt, pepper, and paprika.

Fold cooked macaroni into the cheese sauce.

Remove meatloaf from oven. Carefully spread the mac and cheese evenly over the meat layer.

Return to oven and bake for another 15 minutes, until the top is bubbly and slightly golden.

Let it rest for 5-10 minutes before serving.