A lot of mint freshness in a cool coffee drink - I like it but I know it isn't for everyone (coffee purists?). I made per the recipe except subbed 10 ml rich syrup for the 2t sugar (per suggestion in the comments). No meaningful chocolate notes (IMO) - but I'd need to try head to head to try to discern for sure. Fresh out of the shaker this has wonderful milk caramel color, that gradually is lost as the bubbles migrate to the surface (see pic on the site) - serve to guests quickly!
Also, i see in the history that they used Fernet Branca Menta, which is a different thing than what is listed in the recipe. However, i can't find Fernet Branca Menta as a ingredient on the site