Press saute on the Instant Pot and allow the pot to read HOT. Once hot, add in butter and allow to melt. Once melted, add in ground sausage and brown until finished; about 5 minutes. When meat is browned push cancel.
To the pot, add in macaroni noodles, water and cayenne pepper and stir to combine. Place lid on Instant Pot and press manual feature and adjust time to 6 minutes.
When done, allow for a quick release of the pressure. When pin drops, open lid carefully and press cancel.
Press saute feature again and add in cubed cream cheese and stir. When starting to melt, add in shredded cheese and stir until melted.
When cheese is melted, add in pimentos and cooked broccoli and stir to combine.