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 Nestlé 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.
1. 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.
2. 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.