Microwave cauliflower in microwave safe container and cover with plastic wrap to keep the steam in.
Cook until cauliflower is very well done (approx. 8-10 minutes). Drain. When cauliflower is cool enough to handle, squeeze as much water out of it as possible. (You can drain it right in the plastic wrapper it comes in by poking holes in the bottom). Next, put the cauliflower into a food processor (s-blade) and whir on high for a few minutes (or hand mash for several minutes). Add the cream cheese, and butter. Mix well; the whole point of this process is to make the cauliflower creamy and smooth. Check the consistency. If it is too thick for you, add a tiny bit of cream, mix, and check again. Too much liquid and you will end up with soup (hence the draining!)
Then add ranch powder, pepper, and/or grated parmesan as desired.