Did it with Wódka Żołądkowa Gorzka de Luxe, Borghetti coffee liquor, Lavazza Espresso Italiano and an amber maple sirop. Added drops of my new marvellous Smoked vanilla Bitter from Beeter. I like it, would up the bitter/sour scale up to 7,5 though (but I like it).
I think this is becoming one of my favorite coffee cocktails, though I like to tweak it. Swapping the vodka for a clear rum is quite nice. Upping the maple syrup makes it practically a different drink, but a tasty one. Replacing 30 ml of espresso with 30ml of ristretto cuts down on the bitterness. I don't do all of these at once, just one or two depending on what I want at the moment.