Chewy glutinous rice balls floating in sweet soup are a festive family dessert. A traditional treat symbolizing togetherness and family unity.
Toast the black sesame seeds in a dry skillet over medium heat for 3–4 minutes, stirring constantly to avoid burning.
Grind the toasted sesame seeds, mix with sugar and melted unsalted butter to form a soft filling, then chill for 20 minutes.
Combine glutinous rice flour with water, knead until smooth and soft, then divide into small balls about 1 inch diameter.
Flatten each rice ball, place chilled sesame filling inside, carefully seal, and roll into a smooth sphere while preventing cracks.
Bring 5 cups water, rock sugar, and ginger slices to boil; gently drop rice balls into simmering soup, cook until they float and simmer another 2 minutes for even texture.
Ladle soup and rice balls into bowls, serve hot for optimal chewiness.