Follow these simple steps to create your own Mac and Cheese Meatloaf Casserole:

1. Preheat your oven to 350°F (175°C). Grease a 9×13-inch casserole dish to prevent sticking.
2. Cook the macaroni: In a large pot, bring salted water to a boil and cook the elbow macaroni according to the package instructions until al dente. Drain and set aside.
3. Prepare the meat mixture: In a bowl, combine the ground beef, breadcrumbs, grated Parmesan cheese, Worcestershire sauce, garlic powder, onion powder, salt, and pepper. Mix until well incorporated.
4. Shape the meatloaf: Form the meat mixture into a loaf shape and place it in the center of the prepared casserole dish.
5. Prepare the cheese sauce: In a separate large bowl, whisk together the milk, eggs, sour cream, cream cheese, and mustard until well combined.
6. Combine: Stir the cooked macaroni into the cheese sauce mixture, ensuring it is well coated.
7. Assemble the casserole: Pour the macaroni and cheese mixture around the meatloaf in the casserole dish. Sprinkle the shredded cheddar cheese on top of the macaroni.
8. Add the topping: Evenly distribute the crushed potato chips or panko breadcrumbs over the cheese layer to create a crispy topping.
9. Bake: Place the casserole in the preheated oven and bake for 30-45 minutes, or until the meatloaf is cooked through and the cheese is bubbly and golden brown.
10. Garnish and serve: Remove from the oven, let it cool for a few minutes, and then garnish with chopped green onions if desired.

With these steps, you’ll have a mouthwatering Mac and Cheese Meatloaf Casserole ready to enjoy.