This an amazing chocolate cake which is very easy to make and is sheer heaven if you happen to love tahini. The recipe comes from Stelios Parliaros, a famous Greek pastry chef who has done much to introduce international desserts into Greek homes. It also happens to be completely vegan (or nistissimo) and oil-free. The only thing to watch out for is that the measurements have to be exact or it won't work. Use an electronic scale, measure the ingredients precisely and you can't go wrong.