This cake frosting is named for the length of time it must be beaten in the final stage. Have the cake you are going to frost already prepared before making the frosting; it must be spread on while the beaten egg whites and sugar are still pliable; once frosted, the cake may sit out for several hours before being served.
- Yield: Makes about 5 1/2 cups
Source: Martha Stewart Living, December 2003
- 3/4 cup plus 2 tablespoons sugar
- 1 tablespoon light corn syrup
- 3 large egg whites, room temperature
In a small, heavy saucepan, combine 3/4 cup sugar, corn syrup, and 2 tablespoons water. Heat over medium heat, stirring occasionally, until sugar has dissolved. Rub a bit between your fingers to make sure there is no graininess. Raise heat to bring to a boil. Do not stir anymore. Boil, washing down sides of pan with a pastry brush dipped in cold water from time to time to prevent the sugar from crystallizing, until a candy thermometer registers 230 degrees about 5 minutes. (Depending on the humidity, this can take anywhere from 4 to 10 minutes.)
Meanwhile, in the bowl of an electric mixer fitted with the whisk attachment, whisk egg whites on medium speed until soft peaks form, about 2 1/2 minutes. Gradually add remaining 2 tablespoons sugar. Remove the syrup from the heat when the temperature reaches 230 degrees (it will keep rising as pan is removed from heat). Pour the syrup in a steady stream down the side of the bowl (to avoid splattering) containing the egg-white mixture, with the mixer on medium-low speed.
Beat frosting on medium speed until cool, 5 to 10 minutes. The frosting should be thick and shiny. Use immediately.