Add dry macaroni noodles to the liner of your pressure cooker.
Pour water/broth on top. DO NOT STIR.
Add salt and butter, close the lid and make sure the valve is sealed.
Cook on high pressure for 5 minutes, then quick-release the pressure.
Once the pressure is released and the pin has dropped, open the lid and add the heavy cream, dry mustard, pepper, and garlic powder if using.
Stir in the cheese until melted and creamy.
Serve hot and enjoy!
To reheat you will want to add a little milk to smooth it out. We just use the microwave.