The rice crackers is a binder that holds the hamburger from falling apart! A chewy 100% vegetarian hamburger that doesn't use meat or eggs.
I saw online that the main ingredient in most rice crackers is non-glutinous rice and wheat flour. I figured the starch content could be use to keep hamburger patties together. So I gave it a go.
I used soy sauce-flavored rice crackers. Any flavor such as salt or curry would be fine, as long as it's not sweet. For adults, perhaps chili pepper flavored rice crackers would also be interesting.
Enjoy Japanese food around the world.