The Vietnamese often make two kinds of cakes: banh troi (floating cake) and banh chay (lean cake) on the third day of the third month of the Lunar year.
This is known as the "Cold Food Festival". In Vietnam, most people may have forgotten its origins but it’s still considered an important occasion for ancestral offerings. The cakes are popular desserts in both rural and urban areas.
Banh troi are small white balls made of brown sugar, wrapped in glutinous rice flour. The name floating cakes came about from the way it is actually cooked. Banh chay are also made of glutinous flour, however, they resemble boiled dumplings and are filled with mung bean paste, sprinkled with sesame seeds and served in bowls with syrups floured with grapefrui blossom.