Creating the delicious Mac and Cheese Meatloaf Casserole can be a breeze if you follow these easy steps:

1. Preheat your oven to 350°F (175°C). Grease a large casserole dish or baking pan with cooking spray.
2. Cook Macaroni: In a pot of boiling salted water, cook the macaroni according to the package directions until al dente. Drain and set aside.
3. Mix Meatloaf Ingredients: In a large mixing bowl, combine the ground beef, ground turkey, breadcrumbs, egg, diced onion, minced garlic, salt, pepper, and smoked paprika, if using. Mix well until fully combined.
4. Shape Meatloaf: Transfer the meat mixture into the greased casserole dish. Form into a loaf shape, making sure it fits well in the dish.
5. Layer Macaroni: Top the meatloaf with the cooked macaroni, spreading it evenly over the meat.
6. Prepare Cheese Mixture: In a separate bowl, whisk together the milk, cheddar cheese, and half of the mozzarella cheese until well blended.
7. Pour Cheesy Sauce: Gently pour the cheese mixture over the macaroni layer. Spread evenly to ensure it covers all the macaroni.
8. Top with Remaining Cheese: Sprinkle the remaining mozzarella and Parmesan cheese over the top of the casserole.
9. Bake: Place in the preheated oven and bake for 45-50 minutes, or until the meatloaf is cooked through and the cheese is bubbly and golden.
10. Cool and Slice: Once cooked, let the casserole cool for 5-10 minutes before slicing into portions.

These steps will guide you in whipping up this incredible casserole effortlessly.