Sweet tangyuan with crunchy peanut filling offer a nutty, comforting dessert. A family festival treat served in warm, sweet soup.
Finely chop or pulse the roasted peanuts, then combine with 1/4 cup sugar, butter, and salt to form a crumbly filling. Chill the mixture to help it hold shape.
In a mixing bowl, add glutinous rice flour. Gradually pour in the hot water while stirring with chopsticks or a spatula until most flour is moistened.
Knead the dough by hand until smooth and pliable but not sticky. Cover with plastic wrap to prevent drying.
Divide the dough into 16 equal pieces. Flatten each into a disc and spoon a small amount of chilled peanut filling in the center. Carefully wrap and seal to form smooth balls.
Bring 4 cups water and the soup sugar to a boil in a medium pot. Reduce to a gentle simmer.
Slide the filled tangyuan into the simmering water. Stir gently so they do not stick to the bottom. Cook over medium heat until the balls float—about 3–5 minutes—then simmer for an additional minute.
Serve the tangyuan hot in sweet soup, taking care not to overcook for the best chewy texture.