The dough for these cookies took just a couple minutes to throw together - no planning ahead for softened butter either, as they use just a couple tablespoons of canola oil instead. I used Dutch-process cocoa powder mainly because that is what I primarily have in the pantry - it has a smooth, rich chocolate flavor. However, natural cocoa powder would also work well - it has a slightly bitter edge, but can also be described as having a more rounded note.
Instant espresso powder is used in the dough, however there isn't enough called for to give the cookies a prominent coffee essence. What it does is dance with the cocoa powder to intensify the chocolate flavor - however, you could bump up the amount by a half teaspoon or so if you wanted the cookies to exude a bit more coffee bite. While the original recipe called for light corn syrup, I swapped that out for Lyle's Golden Syrup to give the cookies a mild caramel/burnt sugar background. The dough, once combined, will need to be well wrapped and left to hang out in the refrigerator for at least a couple hours or overnight.
Rolled into balls and dragged through a bowl of powdery confectioners' sugar to give them a snowy coating, the cookies are baked until spread out and the tops bust, leaving behind craggly crevices. Take these cookies out just before they are completely set - if you feel like you need to check, a toothpick placed in the center should have some sticky crumbs attached when pulled out. Be sure to let these cookies cool for at least 2 minutes (and maybe a couple extra, as needed) on the baking sheets - right out of the oven they are fairly soft, but they will firm up as they cool so you can move them to a wire rack.
Chewy through and through, sinking our teeth into these cracked rounds was like taking a bite from a rich brownie, just thinner! I stuck a couple of the cooled ones into a bag and stashed them into the freezer - when I went to take them out to thaw this morning, they looked and ended up tasting just as good as when we made them on Thursday! A tiny bit of the sugar coating on the outside faded away as they came to room temperature, but Jeff didn't even notice when I asked about it. So, I think these would definitely be a good candidate to be made ahead of time!