That is my favourite chocolate cake. My recipe is slightly different: Quick Chocolate Cake TNT
It works fine with whole grain wheat flour (doesn't even matter if it is soft or hard or all purpose whole grain wheat).
I frosted it once. The frosting was delicious, but it detracted from the cake, so I don't do that any more.
I think it is called "wacky" or "krazy" because you mix it in the baking pan.
I never grease the pan, but I serve it out of the pan.