Butter cream frosting with food coloring would work. I know that is available in Europe. As for marshmallow cream, other than ordering it on line and getting it shipped, I'm not sure on that. I see some European producers with it, so I am not sure how they get it.
I'd say you've definitely stumbled onto something mighty close if it isn't the real thing.
How well does it clean up afterward? Never tried marshmallow fluff on its own even, so does it tend to wash out in the shower relatively easy or should I prepare for some extra measures should I get around to trying this?
Thanks for the research, those look like a lot of fun, not to mention pretty tasty given the contents.
It's actually not as bad as it looks to clean up. It doesn't wash out as easily as straight frosting, and acts like it won't washout in the shower for a second. But once you get warm water on it, it melts away. I would say it is a 6 or 7 on the WAM cleanup scale if frosting were a 5, and real melted chocolate we're an 8 or 9. 10 being a 50 gallon tub full of chocolate pudding. Still worth it though!