If you're a chocolate lover, you'll enjoy making Chocolate Tāngyuán. In this version, cocoa powder is added to the sticky rice dough, giving the rice balls a rich chocolatey flavor. The filling can be traditional or you can experiment with chocolate-flavored fillings like Nutella or chocolate ganache. The Chocolate Tāngyuán can be served in a chocolate sauce or even topped with chocolate shavings for a decadent dessert that will satisfy any chocolate craving.