Indulge your sweet tooth with chocolate-filled Tāngyuán. This recipe combines cocoa powder with glutinous rice flour to create a chocolatey dough. Fill the dough with chocolate ganache or Nutella for a rich and decadent treat. The sticky rice balls are then cooked and served with a warm chocolate sauce for an extra dose of chocolate goodness. These chocolate Tāngyuán are sure to satisfy any chocolate lover's cravings.