I was so thinking about this with my Sunrise soaps for the challenge a couple months' ago when I saw this: Tree Marie Soapworks
and there was another Youtube I saw with the 4 pane window frame in the soap and a cat sitting in the window, but I can't find it. I was pretty impressed!
Good luck! Share picture!
ETA: found this too: I Dream In Soap
Thank you @earlene for referencing it. @Tragically Hip the above soap was frame in something similar to a shadow box. The soap is not touching the glass. Since you are interested in framing a shaved piece, I would guess it is much thinner and a regular frame might do. However, I would suggest to find a way to avoid the soap touching the glass as I think it would smear it. Whichever attempt you try, do keep us updated to see how they work.