One autumn in the early Tang Dynasty, a group of Tufan (ancient Tibet) businessmen came to Chang 'an and brought many gifts (refined round cakes) to pay tribute to Tang Gaozu Li Yuan. On the night of Mid-Autumn Festival, Tang Gaozu invited his ministers to enjoy the moon and share the round cakes presented by Tufan merchants. The emperor and his officials ate the cakes while enjoying the moon, and renamed the round cakes as moon cakes, which was the earliest moon cakes.

Mooncake (pinyin: yuè bǐng) is one of the traditional Chinese cakes with a long reputation, and it is a custom in Mid-Autumn Festival. Moon cakes are round and round, and they are shared by the whole family, symbolizing reunion and harmony.

Extended data:

Mooncakes symbolize reunion and should have started in the Ming Dynasty. If we look at the information about moon cakes and Mid-Autumn Festival folklore in the Ming Dynasty, we should be able to see the historical track of the reunion of moon cakes: after the Mid-Autumn Festival, the whole family will sit around and share the moon cakes and fruits (offerings for the moon). Because the moon cake is also round and shared by the family, it gradually forms the implication that moon cakes represent family reunion.

Moon cakes are often filled with plant seeds, such as walnut kernel, almond, sesame kernel, melon seeds, hawthorn, lotus seed, adzuki bean and jujube paste, which have certain health care effects on human body.

References:

Mooncakes-Baidu Encyclopedia