I got this drink out of Dr. Cocktail's always-useful Vintage Spirits & Forgotten Cocktails. The cocktail originally comes from the Café Royal Cocktail Book published in 1937. For more about the Café Royal and it's eponymous cocktail book, check out Our Libatinous Nature and their review of this cocktail.
1 oz bourbon
1 oz apple brandy
1 oz passionfruit syrup (B.G. Reynolds')
1 tsp lemon juice
2 drops orange flower water
Combine all ingredients, shake with ice and strain into a chilled cocktail glass.
The nose is an interesting melange of the oak and corn bourbon notes with restrained fruit from the apple brandy and passionfruit. Using passionfruit syrup gives this drink a fantastically creamy mouthfeel. The sip opens with fruit from the syrup and apple brandy, which transitions to bourbon, then back to the passionfruit. It finishes with the orange flower water. A very elegant cocktail.
A few notes about the way I put this together. The drink originally called for passionfruit juice rather than syrup and a dash of grenadine. As per VSFC, I subbed in passionfruit syrup and balanced it with a bit of lemon juice. I think this worked out well as the drink was sweet without becoming overwhelming. Lastly, Paul Clarke and I appear to think the same way as we both reached for Weller 12 Year bourbon, as its soft wheat mashbill makes it a good pairing with the apple brandy and passionfruit. A rye-recipe bourbon might give the drink a bit more pep, but I like the way everything comes together in a very smooth fashion with a wheated bourbon.