I have an awesome fudge recipe that uses cocoa powder...it makes a sugary-type fudge (v the creamy-type fudge) that we all just love. And it's easy to make.
Butter the bottom and sides of a pie pan.
3 T cocoa powder
2 c sugar
2/3 c whole milk (it has to be whole milk or the fudge won't set)
Mix together in a non-reactive pan and put over medium heat. Without stirring, bring to the medium-hard ball stage.
Remove from the heat and let sit for a couple of minutes.
Add 1 T butter (I use unsalted) and 1 t vanilla. The mixture will sizzle when you add the vanilla.
Start stirring :-) It will be really runny at first, but will start to thicken. If you stir too long (and it gets too thick), you won't be able to turn it out into the pie pan.
Pour it into the pie pan. Let it sit for a couple of minutes, and then score it in squares with a regular butter knife.
Let the batch cool completely and re-cut the squares.
It will melt in your mouth.