Preheat your oven to 375°F (190°C). Grease a 9×13 inch baking dish.

In a large bowl, combine ground beef, breadcrumbs, Parmesan cheese, egg, milk, garlic powder, onion powder, salt, and pepper. Mix until well combined.

Press the meat mixture into the prepared baking dish to form an even layer.

Bake the meatloaf layer for 20-25 minutes, or until fully cooked.

While the meatloaf is baking, cook the elbow macaroni according to package instructions until al dente. Drain and set aside.

In a large saucepan, melt the butter over medium heat. Whisk in the flour and cook for 1-2 minutes, stirring constantly.

Gradually add the milk, whisking continuously until the sauce begins to thicken.

Stir in the mustard powder, smoked paprika, and shredded cheddar cheese. Cook until the cheese is melted and the sauce is smooth.

Add the cooked macaroni to the cheese sauce, stirring to combine.

Spread the mac and cheese over the baked meatloaf layer. Sprinkle the shredded mozzarella cheese on top.

Bake for an additional 15-20 minutes, or until the cheese is melted and bubbly.

Garnish with fresh parsley before serving. Enjoy this hearty Mac and Cheese Meatloaf Casserole!