Preheat the oven to 400 degrees. Place the grapes on a large baking sheet, drizzle with olive oil, and then season with salt and pepper. Put sheet pan on the middle shelf of the oven, and roast grapes for about 25 minutes, until they’re shriveled and soft. Stir the grapes every 10 minutes, drain off and reserve any liquid that has pooled in the pan because this will keep the grapes from properly roasting. In a heatproof bowl or container, mix the roasted grapes with the reserved liquid and date syrup.
Brush each side of the baguette slices with 2 tablespoon of olive oil. Arrange on a baking sheet and toast for about 8 minutes, until golden and crisp. Let cool.
To assemble the crostini, spread each slice of baguette with about 1 tablespoon of goat cheese and spoon the warm grapes on top. Arrange on a platter and sprinkle the crostini with salt and pepper.