Original Hanky Panky recipe from The Savoy Cocktail Book:
2 dashes Fernet Branca
½ Italian Vermouth
½ Dry Gin
“Shake well and strain into cocktail glass. Squeeze Orange peel on top.”
As referenced by Difford, Simon. Diffordsguide Cocktails, The Bartender’s Bible. 10th Edition, Odd Firm of Sin.