Seven minute frosting’s main virtue is that it’s fast to make and gives you, for ten minutes of effort, a silky and luxurious frosting that’s light and fluffy and sweet rather than rich (for those who can’t deal with the heaviness of a buttercream). You whip it up while your guests are finishing their meal, throw your cake together and serve it. Sure it’ll hold for longer than that, but not terribly much longer. The frosting begins to firm and crystallize as soon as it cools. It gets slightly gummy after an hour, has a crust on it after two hours, and is often hard as baked meringue a day later. So it’s an ephemeral treat, but well worth doing for a truly homespun layer cake experience.
Careful readers will note uncooked egg white in this recipe. If that bothers you, pasteurized egg whites are available in most supermarkets in the States. There’s so much sugar in this recipe that it seems (at least to me) impossible that any microbes could grow in it. But act according to your own preferences. Set a pan (or the lower half of a double boiler) with about two inches of water on the boil. Place all your ingredients save for the vanilla into a metal bowl (or the top of a double boiler). Have a hand mixer at the ready.
Beat everything on medium-high for about a minute to combine.
When the water is boiling, put the pan over the water, making sure no water is touching the bottom of the pan.
Whip for seven minutes until it looks like this:
Beat in the vanilla or any other flavoring you’d like to use. A chocolate version can be made by folding in about three ounces of melted dark chocolate. It will incorporate readily into the warm foam. Use the frosting right away as it will start firming as soon as it cools.