I had a black bean brownie today, normally I steer well clear of stuff like this but it did look nice and it was really really nice.
It was made with cacao, not sure on the difference between that and cocoa. I think it must have had coconut and honey in it, perhaps date paste or something, not sure.
There are tons of recipes online of course but I have also read in the past that these sort of brownies end up tasting of bean so I never bothered (I wanted to make some last year), but having had this one today I really was impressed
I wouldnt say it was like a brownie, more like a fudge, very dark and hardish, had to press down quite a lot with the fork to get through it.