I replaced the tung min flour with tapioca flour since I didn't have tung min flour. I also added more water than desired. My colleagues tried it today and they commented that the yam cake tasted really good! There were a lot of ingredients in the cake and was very flavourful! It was a case of kitchen-mishap-turned-lucky! I was glad I tried to salvage the batter, if not, I would probably have given up on making the yam cake!