You can make these rice cakes without a rice cooker (I did) but according to the author, it doesn’t turn as good. Mines were pretty awesome I have to say.
Place all the ingredients into a rice cooker and cook according to your machine’s instructions. When cooked, mix everything together until it is smooth and spoon the hot mixture into an airtight zip fastener freezer bag (size large or medium depending on the brand)); flatten out to roughly 4cm deep and smooth the air out. Once cool, refrigerate overnight. Remove carefully from the bag, cut into approximately 20 squares and keep in an airtight container in the fridge. If refrigerated, they will keep for about four days. When using on a bike, wrap in silver paper – the best to use the type that is silver foil on one side with baking parchment on the other.