Wonderfully deep and nuanced. An instant favorite. And also a recipe to explore. I tried it with different sorts of rum but returned to gin eventually. Not a (London) dry type, but a more mellow one. In my case, Isle of Harris Gin.

Tried it with Averna and gin and really enjoyed it.
Followed Michael Z's suggestion and substituted Ron Zacapa for the gin and WOW!
Deep and contemplative indeed!

This is a "grown up drink" (my boyfriend's assessment).

I may never leave the house again.

PS Don't skip the orange twist

A lovely, restrained sipper. We thought commenter Michael's suggestion worth a try and used Plantation Original Dark in place of the Gin...made, for us, a deeper, more contemplative drink, equally lovely.

This was great! I made this with Lustau Palo Cortado Peninsula, Amaro Meletti, (unaged) Genever from Wigle in Pittsburgh, Ancho Reyes and Angostura Cacao bitters. Unusual build that I want to explore more.

Very tasty.
(I've tried with 15 ml of Vecchio Amaro del Capo and 20 ml of dark rum (Havana Club 7 años) instead of gin).