Cheryl made some brownies the other day and very kindly saved some for ice creaming. After extensive debate, we decided on mint coffee ice cream with brownie bits in it. The original idea was to have the mint be throughout the base, the coffee in swirls, and the brownies in discrete bits, so all three flavors would be in distinct modes. That didn't happen. 
I need to figure out a proper way to do swirls in ice cream. Cheryl did diagram all the options we considered. We went with option B (which didn't work), separating out some of the cream to mix the coffee into and add later, but it ended up still just mixing evenly throughout. If anyone has tips, let me know. I think maybe we should have mixed coffee into a portion of almost-finished ice cream, then put that back in, but I don't know how well the coffee would have blended (i.e. the granules wouldn't dissolve). That would have been option A or C, depending on the timing. Anyway, about the recipe itself. The mint part is easiest -- just a tsp of peppermint extract in a sweet cream base. Ben & Jerry's coffee recipe (pg. 66) says to use 3 tbsp of coffee, but we only used about half of that, which I think cooperates better with the mint. Then just crumble in a bunch of the brownies. I'm not the biggest fan of coffee or straight coffee ice cream, but this combination is nice.