An agave-based old-fashioned with a wonderful hit of smokiness from the mezcal (depending on your choice of mezcal).
Like many cocktails, Philip Ward's...
Agree with prior comment, much easier to stir agave syrup in with room temperature licores, then add ice cubes. No chocolate bitters, so used a few drops of our local Heritage Distilling Cocoa Bomb whiskey and a dash of orange bitters - delicioso for Dia de los Muertos!