Bill Kates supplied this recipe as he made it on his very first job when he moved to Boston. He took the job as a soda jerk because he loved the Hot Fudge Sauce at Bailey's Ice Cream Parlor of Boston, Mass. I found the recipe inside his review of Recipe#202009 #202009, and was surprised he had not posted this version himself. Hot Fudge is serious in our family, so I made both the version Bill K made on the job and Recipe#202009. The result of my taste test war? Whatever chocolate you use, that quality will determine the quality of your sauce; skimp, and the taste suffers. I used Hershey's cocoa powder by accident when I made this version, and the distinctive Hershey's taste came through loud and clear. Except for the chocolate source, the end result of both recipes came out about the same. I prefer working in a double boiler because it is easier to keep the chocolate from getting too hot.