Toss them in the frying pan for a few minutes and they get all warm and chewy in the inside and crispy in the outside. Splash a little soy sauce on top and it's heavenly.
my grandmother used to do this for us as an after school snack, using fresh mochi she made (but with just regular white rice flour). she'd fry them up in sesame oil & splash soy/vinegar on them after. awesome with ponzu sauce, too.