2. Drain the raisins, reserving the liquid. Discard the vanilla bean. Put the liquid back in the saucepan and bring to a boil. Reduce to about 1/3 cup, or until the syrup turns a deep golden color, 10 to 15 minutes. Watch carefully so the syrup doesn't burn. If it starts to foam, remove from heat immediately. The syrup will continue to thicken as it cools, and have a texture similar to light maple syrup. Cool completely.
3. Preheat the oven to 400 F.
4. Brush butter onto both sides of the bread slices. Bake for 8 to 10 minutes or until golden brown. Let cool completely.
5. To assemble: Put a slice of cheese on each toast. Sprinkle with a few raisins and drizzle syrup over the top.
Note: If you have any raisins and syrup left over, combine them and refrigerate in an airtight container. They will keep for 2 weeks.
Darra Goldstein is editor in chief of The Oxford Companion to Sugar and Sweets, an 888-page reference guide to all things sweet. "The book is really a compendium of human desires, a cultural history of desire for things that are sweet and what it has caused in the world, in both the realm of pleasure and also of pain," she says.