I was just recently in Shanghai and each night when walking home, I noticed some vendors selling a mystery street food and I never found out what it was. The vendors were always located along Wusong Road, right around the bridge that crosses Suzhou Creek. They seemed to only be out in the evenings.
The food was some sort of dense cake or bread of some type. It had a dark color and was very ornately decorated with nuts, dried fruit and candy in the shape of fruit or vegetables. The cake came in a huge slab approximately 24"x36"x4" and they sold it from the back of bikes with a platform on the back where the cake sits. It looked like they sold it by the slice or chunk because I would see the same people each day with ever decreasing cakes.
I have no idea what it was, but I'm still curious. Please let me know what it was if you know what I'm talking about. I don't think I got a photo of it, but my friends may have, so if I can I'll post a photo.