In a small, heavy saucepan, combine 1 1/2 cups
sugar, the corn syrup, and water. Heat over medium,
stirring occasionally, until the 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 the sides of the pan with a pastry
brush dipped in cold water to prevent the sugar
from crystallizing, until a candy thermometer registers
230F, 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 the egg whites
on medium speed until soft peaks form, about 2 1/2
minutes. Gradually add the remaining 1/4 cup sugar.
Remove the syrup from the heat when the temperature
reaches 230F (it will keep rising as the pan
is removed from the heat). With the mixer on
medium-low speed, pour the syrup in a steady
stream down the side of the bowl (to avoid splattering)
containing the egg white mixture.
Beat the frosting on medium until cool, 5 to 10
minutes. The frosting should be thick and shiny.
MAKES ENOUGH FOR ONE 9 -INCH 4 - LAYER
CAKE OR 12 JUMBO CUP CAKES