I know its a bit delayed and you probably have it by now......
I'm tyring to make this for thanksgiving and the link on martha stewart is broken but I found the reciepe by googling it :)
Mrs. Milman's Chocolate Frosting
While this frosting is cooling, you'll need to stir it as instructed; otherwise, the frosting around the edge of the bowl will harden and the frosting at the center will remain liquid. The finished frosting should have a consistent texture. Lois Milman, the creator of the frosting, always uses Nestl; morsels and makes only one batch at a time. Spread the icing on Moist Devil's Food Cake as soon as it is sufficiently chilled; it holds its shape well on the cake.
Serving: Makes 6 cups.
24 ounces Nestlé semisweet chocolate morsels
4 cups whipping cream
1 teaspoon light corn syrup
Place chocolate morsels and cream in a heavy saucepan. Cook over low heat, stirring constantly with a rubber spatula, until combined and thickened, between 20 and 25 minutes. Increase the heat to medium low; cook, stirring, 3 minutes more. Remove pan from heat.
Stir in corn syrup. Transfer frosting to a large metal bowl. Chill until cool enough to spread, about 2 hours, checking and stirring every 15 to 20 minutes. Use immediately.