In a small bowl sift together cocoa powder and powdered sugar
In a separate small bowl, start whipping the heavy cream with a hand mixer on low.
Just as the cream starts to thicken add the sugar/cocoa mixture and the vanilla
Continue whipping on high until it becomes thick. Be careful not to over whip! You will end up with chocolate butter. Which could be a whole new amazing thing, hmm…
Use immediately or store in refrigerator for up to 3 days.