From Maida Heatter's Book of Great Chocolate Desserts

• 1/2 cup heavy cream
• 3 Tbsp sweet butter, cut into small pieces
• 1/3 cup granulated sugar
• 1/3 cup dark brown sugar, firmly packed
• pinch salt
• 1/2 cup strained Dutch-process cocoa powder (don't substitute - it must be Dutch process for the right color and flavor)

Stovetop:

1. Place the cream and butter in a heavy 1-quart saucepan over moderate heat. Stir until the butter is melted and the cream just comes to a low boil. Add both sugars and stir for a few minutes until they are dissolved. (The surest test is to taste; cook and taste until you do not feel any undissolved granules in your mouth.)
2. Reduce the heat. Add the salt and cocoa and stir briskly with a small wire whisk until smooth. (If the sauce is not smooth - if there are any small lumps of undissolved cocoa- press against them, and stir well, with a rubber spatula.) Remove from the heat.

Microwave:

1. In a 1 qt pyrex cup (or saucepan, if cooking on stovetop) mix sugars, cocoa, and salt; add cream and mix thoroughly to wet all.
2. Place butter on top and MW on high until mixture begins to boil.
3. Stir well, until butter melts into mixture, then MW 2 min. on med-low - 3-4 setting - being sure it doesn't boil over.

Serve immediately or reheat slowly, stirring frequently, in the top of a double boiler over hot water, or in a heavy saucepan over the lowest heat.

• This should be thick, but if it is reheated it may be too thick. If so, stir in a bit of hot water, adding very little at a time.
• Hot fudge is made by boiling together cream, sugar, chocolate, and sometimes butter—the traditional ingredients for fudge—into what is essentially just an undercooked, unset version of the confection. It differs from plain old chocolate sauce by virtue of being gooier and more viscous.