Mac and Cheese Meatloaf Casserole

Ingredients:

For the Meatloaf Layer:

1 pound ground beef
1/2 cup breadcrumbs
1 egg
1/4 cup ketchup
1 tablespoon Worcestershire sauce
1 teaspoon garlic powder
1 teaspoon onion powder
Salt and pepper to taste

For the Mac and Cheese Layer:

2 cups elbow macaroni, cooked
2 tablespoons butter
2 tablespoons all-purpose flour
2 cups milk
2 cups shredded cheddar cheese
1/4 teaspoon mustard powder (optional)
Salt and pepper to taste

For Topping:

1/2 cup shredded cheddar cheese
1/4 cup breadcrumbs (optional)