I had a chance to stopping by at Dean and Deluca, Bangkok today and found that the Original Sacher Tort is there. Just FYI to anyone that wants to try. Pricing at 290 baht/piece is very expensive for a piece of cake though.
(This is the cake I'm referring to http://www.sacher.com/en-original-sac...)
I'm not sure if all D&D would offer this cake but there is one drink that I'm pretty sure it's unique to Bangkok branch, mango with sticky rice milkshake :) Well, it's creamy and smooth with gentle mango flavour and sticky rice flowing through the straw (well, I think it's the same concept with bubble tea)...The novelty was nice but overall it's just too rich for me to complete that 16 oz cup by myself. The richness and texture actually reminded me another Thai dessert, durian with sticky rice, instead.