Put the noodles, water and salt in the Instant Pot.
Cover the pot and make sure the vent on the top of the cover is set to "Sealing".
Press the "Pressure Cook" or "Manual" button. Set timer to 3 minutes.
Once the noodles are done cooking, switch the vent to "Venting" and do a quick pressure release, turn Instant Pot off.
Carefully open the lid. Press the "Saute" button and then add the evaporated milk, butter and cream cheese. Mix until butter and cream cheese is melted.
Turn off Instant Pot. Add shredded cheese and parmesan cheese, mix until cheese is melted.
Add bacon pieces and serve immediately.
FOR THE SLOW COOKER:
Follow package instructions for preparing the macaroni noodles, but cook the noodles only half the amount of time as it calls for on the package instructions ( ex. If the package says cook for 10 minutes, only cook for 5 minutes). Drain. Pour macaroni into slow cooker.
Add evaporated milk, butter, cream cheese, shredded sharp cheddar cheese and parmesan cheese. Stir together well.
Cover and cook on high for 3 hours, stirring occasionally. Serve with bacon pieces.
Notes
You probably won’t have any leftovers because this macaroni and cheese is so good but if you do it heats up perfectly in the microwave. If you want it more creamy just add a little bit of milk to it before you put it in the microwave.