Mix Parmesan cheese and breadcrumbs together; set aside.
Remove from heat, add grated cheddar and white cheddar cheese, stir until melted. Adjust seasonings as needed.
Beat the egg and mix into the sauce. Combine cooked macaroni with cheese sauce, mix well.
Spoon into prepared muffin pan, gently pressing the mac and cheese so it is compact. Top with breadcrumb mixture.