Bánh bao (literally “wrapping cake”) is a ball-shaped bun containing pork or chicken meat, onions, eggs, mushrooms and vegetables, in Vietnamese cuisine. It often has Chinese sausage and a portion of a hard-boiled egg inside. Bánh bao are generally smaller than baozi, and are filled with savory fillings, the most popular of which is seasoned ground pork. A vegetarian version of bánh bao also exists.
The dish originated with the baozi from China but was adapted by the Vietnamese and is also available in most other countries with significant Vietnamese populations. As in China, pork is the most popular kind of meat in Vietnam.
Bánh bao is an old fashioned Cantonese dim sum called tai pao (literally “big bun”) brought to Vietnam by Cantonese immigrants.
Source: wikipedia