In a small saucepan, simmer the balsamic vinegar and rosemary on low until they reduce to a syrup consistency (about 10 minutes). Set aside to cool briefly. Pour the reduction through a fine mesh strainer into a small bowl to remove the rosemary pieces.
Toast the bread. If this recipe is to be shared with a crowd, then place the bread slices on a tray and cook in a 350 degree oven until bread is lightly toasted. Once the bread is lightly toasted, remove from the oven or toaster and gently rub the top of each slice with the clove of garlic.
For a crowd, consider assembling right before your guests arrive. Depending on the size of the toast, spread the toasts each with about 1 teaspoon (tsp) of goat cheese, then about 1 teaspoon (tsp) of Fig Preserves, and then loosely place one or two slices of prosciutto on top.
Right before serving, drizzle the crostini with the balsamic reduction or leave on a tray for guests to help themselves.
