In addition to the puffed rice and the cardamom powder, you can add a lot of other add-ons to these delicious sweet treats.  Crushed nuts like peanuts, walnuts and pistachios can be great additions to the puffed rice balls. If you are allergic to nuts, you can use seeds instead.  You can also choose to add your favorite cereal in addition to puffed rice to bring in a bit of variation.