Ballantine's Finest, Tia Maria and Angostura cocoa bitters, along with what little syrup stuck to my bar spoon after lifting the cherry out of the jar - earthy and fairly dry in a way that highlights the common ground between the scotch, coffee and chocolate, but with just enough sweetness to round them out. Lovely!
Oh, this one's good - muddling your cardamom pods well is key however, make sure to crush them open (depending on your muddler, you may have better luck using the handle side like I did). Used Havana Club 3 Years instead of my El Dorado 3 by accident and added a dash of Peychaud's to stand in for the daiquiri bitters, need to try with the other rum soon.
Didn't nix the sugar syrup, did add two dashes of cocoa bitters per people's tips here. Scotch, lime and chocolate make for odd bedfellows - but it works, and I like it.