Heat oven to 350 degrees F. Spray a muffin tin with cooking spray and set aside. In a medium sized pot, boil water with ½ tsp salt. Once boiling, add elbow macaroni and cook for 8 minutes. Remove from heat, drain, and place back into the pot. Add half the amount of cheese, egg, butter, remaining salt, pepper and stir well. Then stir in milk.
Scoop macaroni and cheese into the muffin tin. Once the tin is full, sprinkle bread crumbs and remaining cheese onto the top. Place in oven and bake for 30 minutes.