Preheat oven to 425ºF.
In a pot, combine raisins and water.
Boil for about 5 minutes and then add the
brown sugar, cornstarch, cinnamon and salt. Stir until clear.
Remove from heat and then add vinegar and butter.
Let cool slightly and pour into pastry lined pie pan. Cover with top pastry.
Bake for about 30 minutes or till golden brown.