A traditionally American liquor distilled from fermented apple cider, traditionally using a method known as freeze distillation, in which cold temperatures are used to freeze out the water in the 5-7% alcohol cider to the point that it is 40-50% alcohol. Prior to the required pasteurization, the hard cider base could be made simply by leaving store bought cider (kept in a glass jug with a metal cap, to allow airflow) in the sun. With modern sterile cider, both sugar and yeast must be added.
Unpasteurized cider may still be bought from farmers and hippies, but champagne yeast is already available, and there are countless recipes available on the Internet that will have your average high school alcoholic brewing his own alcohol in minutes.
Apple Jack can be made year round using store bought ingredients. The extreme cold needed to freeze alcohol (-117 deg. Celsius, really fucking cold!) means you don't even need a freezer; dry ice, available from behind the counter in many grocery stores, may simply be soaked in the yeasty beer to collect water ice.