OK, the process is called chocolate panning, and there are $70,000 machines that do 150 pounds at a time, and seemingly there is a tabletop unit but the link I found was dead. Of course, there may be other DIY processes, developed "in the field" in the world of nut and kettle-type concessions.

I’ve been searching on the internet for a modestly high-volume way to coat nuts or coffee beans with chocolate. I keep getting bogged down with home-kitchen recipes that amount to a handful on wax paper. I did see a picture of a small piece of equipment that was shaped like a brass concrete mixer, but there was no link to the manufacturer or even a name for it. Anybody have any ideas?