Just made this again, and what a knockout drink!
This time I used Cocchi Storico - and I shook it (don't judgr me!) An absolute belt of vanilla, which doesn't get a mention in the tasting notes for the Cocchi, so maybe my tastbuds are out of whack, but this is one classy tipple - not as hairy-chested as a dry martini, but every bit as serious.
Go on - treat yourself!