@Beguile,
I have no special fudge recipe, just add a generous teaspoon of cornstarch to the sugar in any fudge where you actually cook the butter, sugar and milk on the stovetop. I have never had a fudge failure using cornstarch, whether I make Fudge, peanut butter fudge, or an old-fashioned chocolate fudge.
I do not make microwave fudge; this tip only applies to a cooked fudge where you either cook X amount of minutes, or to a soft ball stage.