Black Satin Sauce

Heat cream and butter until butter melts, add sugar and heat until it melts, sift in (pour a little at a time through a fine strainer) cocoa, bring to boil, done. Makes about a cup of sauce that is runny when hot, solidifies to chewy on ice cream, and is thicker than tomato paste when refrigerated. I don't know why but if you simply mix all the ingredients and bring to a boil it doesn't get as thick.