I had a chance to try chocolate MMF this weekend. I just added cocoa powder to the melted marshmallows. Mine didn't really get that dark, maybe I should have added more. The recipe I used was half a pound of MM and I added up to 4 tbsp. of cocoa. I had to add brown and a bit of black colour. I found that the MMF was a bit dry and hard to work with. But it tastes marvelous! I always find myself taking a piece !