Combine elbow macaroni, water, heavy cream, ¾ of the cheese, dry mustard, kosher salt, black pepper, and garlic powder in a 7-inch pan that is deep enough to hold all the ingredients. Stir to combine.
Place in Air Fryer basket and set Air Fryer on 360 degrees Fahrenheit. Set the timer for 18-20 minutes and start Air Fryer. Halfway through cooking, open the Air Fryer basket and add remaining cheese and stir. Close and continue cooking.
Once the Air Fryer is done cooking, open Air Fryer and stir the mac and cheese. Remove the pan from the basket and allow it to cool for 5-10 minutes. The mac and cheese will thicken while it cools. Serve and Enjoy :)
Various Air Fryer brands cook at different speeds. Check on your mac and cheese around the 18-minute mark. If the noodles are al dente, your mac and cheese can be removed from the Air Fryer.