Mooncakes (月饼, Yuèbǐng) are pastries eaten on the Mid-Autumn Festival, which occurs on the fifteenth of the eighth month on the Chinese calendar, which is on the 30th of September this year. Traditional mooncakes come in a variety of fillings, like white lotus seed paste, red bean paste, and five kernel—most of which traditionally contain at least one salted duck egg yolk in the middle.
The history of the pastry dates back to the Yuan Dynasty (1280-1368 A.D.), when the Mongolians ruled China. To spread the word of a rebellion against the foreign rulers, special cakes were made with messages hidden inside. On the night of the festival, the rebels attacked and successfully overthrew the government. The mooncakes are eaten to commemorate this legend.