The Adventures of Mary-Kate & Ashley: The Case of the Volcano Mystery
The girls receive a call from some miners of marshmallows that a snowball-throwing monster has been "terrorizing" them. The girls eventually find out that the "snow" is really ash, and the "monster" is actually a geologist warning them that an active volcano is not a safe place to work.
Directors: Michael Kruzan
Writers: Dan Zettel, Michael Kruzan
IMDB: tt0283857