your mixer. Sift or stir 1 cup of the sugar with the cocoa powder and mix into the cheese and butter. Add some cream if the stuff gets too dry. Continue adding sugar, and cream as needed, to a spreadable consistency. Beat well to get all the lumps out.
The exact measurements for the dry stuff is unimportant. Sometimes (Ok, all the time!-), for a more bittersweet flavor, I will add more cocoa powder to taste