1   pastry dough (for a 9-inch single-crust pie)
1/3 cup raisins
1/4 cup light brown sugar
2 tablespoons granulated sugar
2 tablespoons unbleached all-purpose flour
2 tablespoons bourbon
1 lemon (grated zest)
1 tablespoon lemon juice
3/4 teaspoon ground cinnamon
1/4 teaspoon ground nutmeg
1 3/4 pounds tart apples, such as Granny Smith (peeled, cored and cut into 1/8-inch thick slices, 6 to 7 cups)
2 tablespoons melted butter
  Rich Vanilla Custard or ice cream (to serve, optional)