My wife loves sweet potatoes (aren't they also yams, i.e. just a synonym?). I bake her two to my one regular potato. All are slathered with butter, holes poked in to prevent explosion. I cook my spuds over an hour and spray them with spray oil 2 or 3 times; her sweets I take out at about 40 to 45 minutes. We both love them that way, just whole. But she also likes me to cut her sweets up and make a soup much as described above in this thread. I do not puree them, however.
Squash and pumpkins are not my favorites (but I love making home made pumpkin seeds