Do you have anything you can use as a replacement? Regular cookies work just fine. They're just thin, slightly sweet really crumbly cookies. You can make them with any cookie though. As long as you have marshmallows and chocolate, you're set!
This is lovely! When I first glanced, I thought the marshmallows in the back were a bowl of mushrooms for a split second. Which gave me the need to suggest you try mushrooms next time you have an art block! (: