Arrange one of the pie crusts into the bottom of a deep dish pie pan.
Fill the pie shell with the apples.
In a medium pot, whisk together sugar, flour, salt, water, and apple cider vinegar.
Cook over medium heat, stirring constantly, until thick.
Remove from heat, and add butter, vanilla, cinnamon, and Fireball whiskey.
Pour mixture evenly over the apples.
Arrange the top crust, and pinch edges to seal. Prick with a fork.
Bake at 400 degrees for 45-50 minutes, or until pie is golden brown, and the apples feel soft when a toothpick is inserted near the center.
Remove to a wire rack to cool.
Serve with ice cream or whipped cream.