For my own reference, in case the original site has gone away for good:
INGREDIENTS
o 1 cup sugar
o 6 T corn starch
o 4 T cocoa
o 1/2 t salt
o 1 cup water
o 2 T oil
o 1/2 t vanilla
METHOD
Mix sugar, cornstarch, salt, and cocoa in a medium sauce pan. Whisk in the water. Heat over medium until it gets thick and starts to boil. Boil for 1-2 minutes (make sure you don't boil too long, or it will set like toffee). Remove from heat and stir in oil and vanilla. Cool and spread on cooled cake.
Enjoy!