The electric stove I grew up with had a burner that could be dropped down and serve as the heating source for a double boiler or steamer. Years ago when I purchased my first crock pot there was an offer in the box to mail in and purchase both a grill rack for the inside and a covered insert to use as a double boiler or steamer. I don't think these inserts are still being offered. I have used mine for years and really cherish it.
This time of year...the first snow is scheduled to arrive this afternoon..is when I break it out. My favorite recipe is a cranberry steamed pudding that my mother used to make. It takes 5 1/2 hours in the crock pot. It is served either with a "soft" or a "hard" sauce. In the past I have also made a great carrot cake in the steamer. I think I shall do some more playing since we have extra mouths to feed who both have a sweet tooth.