I know this is an old post but for anyone still wanting this recipe here it is- just as good and easy as the old box mix and much cheaper. This recipe is best made with an electric mixer, or even better with a stand mixer to save your arm.

FLASH FROSTING

1 egg white
1 cup sugar
1/2 tsp vanilla
1/4 tsp cream of tartar
1/2 cup boiling water

Mix all except boiling water in large mixing bowl.

Add boiling water all at once and beat 5 to 7 minutes on high until light fluffy and good spreading consistency. Don't overbeat or it turns into something suspiciously like divinity.

Best served same day as made.

Makes a large bowl full.