Concave cake was introduced in 2013 by Kangxi Lai Le and celebrities raved about it which led to a trend in Taiwan.
Concave cake (Chinese: ; pinyin: aodangao, half-cooked cake) became popular in Chinese society after a Taiwanese variety show introduced it. Between the 15th and 17th centuries, the cake was introduced to Nagasaki, a city in Japan best known for its roles in ending the Second World War. Concave cake is believed to have originated from Portugal during the Age of Discovery. 
