01 - Place elbow macaroni, water, and salt into a large microwave-safe mug or bowl.
02 - Microwave uncovered on high power for 4 to 5 minutes, pausing every 1 to 2 minutes to stir, until pasta is tender and most of the water is absorbed.
03 - Stir in milk, shredded cheddar cheese, and cream cheese or butter if using. Mix thoroughly.
04 - Microwave for an additional 30 to 60 seconds until cheese has melted and the sauce is creamy.
05 - Stir well once more and allow to rest for 1 minute before serving.