Bourbon whiskey
The Zazarack was included in the 1910 version of "Jack's Manual", an early cocktail guide written by Jacob "Jack" Grohusko who was the head bartender at Baracca’s restaurant in New York. It called for 100% Bourbon whiskey, 1 dash of absinthe, 1 dash of angostura, and a quarter loaf of sugar. Directions included stirring with ice and straining into an old fashioned glass that had been placed in ice for three minutes.