3 parts applejack brandy
2 parts lemon or lime juice
2 dashes grenadine

Traditionally shaken into a chilled glass, garnished with a cherry or an apple slice, and served straight up.

DC Trivia, via Wikipedia:
In June 2003, the Washington Post published an article entitled "Searching for Jack; Two Guys, One Drink, 60 Bars," that chronicled two writers' quest to find a Jack Rose in a Washington, D.C. bar. After visiting seemingly countless bars, they were unsuccessful in finding one, ultimately buying a bottle of applejack for one of the few bartenders they encountered who knew how to make one. Laird & Company are the only current producers of applejack.