In my opinion, you can find the best chocolate cake in the world in the “Cafe Bros”. The owner is Korean, you can find the cafe near Wudaokou Subway Station. Just walk about 500 m into west direction towards Beijing University at Chengfu Lu, you find it at the left side (and no, I do not get any money for this post)

北京市海淀区

五道口华清商务会馆底商 E 号 ,

Tel. 82863198

chocolate cake in Chinese: 巧克力蛋糕 “qiaokeli dangao”.