In a heatproof bowl slightly larger than the saucepan,
combine the chocolate, corn syrup, and vanilla. Set the
bowl over the saucepan and reduce the heat to low so the
water just barely simmers.
Whisk the ingredients until the chocolate is completely
melted and the ingredients are combined, about two
Remove the bowl from the saucepan and stir in the raisins,
being sure they are all well coated with chocolate.
Use a teaspoon to scoop the clusters on the prepared
baking sheet. When all the raisins have been scooped out,
place the baking sheet in the refrigerator for 10 minutes to
allow the chocolate to set.