I found this recipe on liquor.com.

rum, Cointreau, dry vermouth, grenadine⁣
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I was all set to mix up a gin drink today…then realized there isn’t even an ounce left in the bottle. Ah, well. This drink was popular in Cuba during Prohibition. I’m guessing that plenty of Americans were leaving the US to have this cocktail in Havana (since Prohibition is mentioned), but Wikipedia also says that this became the preferred drink of the Cuban upper class at the time.⁣
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I’m glad I made this today – I’ve been trying to find drinks to use the expensive bottles of vermouth I bought when I first started this project. (I guess I thought more cocktails used dry or sweet vermouth.) It has a richness of flavor that I haven’t tasted in any of the other rum drinks I’ve tried. I’m guessing it’s the vermouth, but vermouth is still a bit of a mystery to me, since I’ve barely used it.⁣