The gac dumpling is a Vietnamese dumpling in which the dough is made of (glutinous) rice flour and the red flesh of gac fruits, and the filling is made of mung bean paste. This gac dumpling is originated in Ninh Giang district of Hải Dương province (in northern Vietnam) which is also famous for another dumpling made of ramie leaves (called bánh gai in Vietnamese).
The traditional red-colored gac dumpling is wrapped in dried banana leaves, in the exact same way with black-colored ramie dumpling. But modern chefs may wrap them in plastic sheets. The shape of the traditional dumplings is flat, while that of the modern ones is round and looks like a tomato.
In a sauce pan, add the mung bean paste, a little salt, and 50 ml cooking oil then stir well on low heat. Add coconut shreds and continue to stir until the mixture is thickened. Let it cool and mix with a little banana essence or vanilla powder. Divide the thickened mun bean paste and roll into small balls.
Slice a gac in halves. Scoop out its flesh, and discard the seeds. In a bowl, knead the rice flour and gac flesh. Add sugar, then slowly pour warm water into the bowl. Continue to knead until the dough is ready. Divide the dough into small portions. Cover the dough bowl with a food wrap and let it rest for 15-20 mins.