This turned out better than expected. It has frozen to the consistency that one expects from ice cream. I used the same base for both this and the pumpkin. After 20 minutes of sitting out I can barely dent the pumpkin with a spoon. On the other hand, the hot chocolate comes right out. I am most puzzled on the difference... I am assuming that it has to do with the different freezing qualities between pumpkin and chocolate.
All is not completely perfect, though. I wish that a little bit more of the hot chocolate flavor carried through. While it was clearly present while the mix was the consistency of a soft cream, the flavor has become very delicate in the fully frozen product. While last night I found the pieces of hot chocolate to be a little annoying, today I find that they help boost the flavor. I'm not entirely sure what to do to remedy this issue, but I will have to experiment a litlte more.
Next up: find some black sesame seeds. I expect that Mitsuwa should provide the solution. Fortunately I have to go over there in the next few days to return and pick up more videos.