Although its origins are unknown, what we do about the Barbary Coast is that it is a Prohibition-era drink. Mixing Scotch, Gin, Crème de Cacao & Cream, this drink takes its name from the nine-block area in San Francisco that was a red-light district frequented by sailors in the mid-19th to early 20th centuries.
Shake all ingredients in an ice-filled shaker then strain into a chilled glass
Grated nutmeg
The drink appears in The Savoy Cocktail Book but there it is served in a highball glass with cracked ice.