You can also add 1/2 cup nuts if you like! And as far as cocoa powder, I've used both Hershey's and a nicer Ghirardelli cocoa - the Hershey's makes great brownies, but the nicer cocoa powders make the brownies so much more fantastic!
You'll need an 8x8 baking pan to make these in, and aluminum foil or parchment paper to line it. :) And an oven preheated to 325 F.
I originally found this recipe on smitten kitchen - but modified it so I can eat it! Butter and I don't play well, and adding coconut oil keeps the brownies nice and rich.