Even the best pastry makers occasionally fail at making génoise batter. The reason, I think, is that it's such a schizophrenic process. You start by beating the dickens out of the stuff, then are forced to suddenly change gears and baby it — for fear of breaking the precious bubbles you've worked so hard to make. It's not a complicated process at all, but one that requires you to have all your ingredients and implements ready ahead of time, and then to move from one step to the next promptly (especially after the foam has been created).

The first step is to have your oven preheated to 350 and your baking pan — be it flat and shallow or round and deep — prepared and waiting. Once that's done, you'll want to finding a saucepan that will comfortably fit your mixer bowl, like so:

Take the bowl off the saucepan, put about an inch of water in it, and set it to simmer. Now then...sift your flour and salt into a medium bowl.

Off the stove top, add your sugar and eggs to the mixer bowl...

...and give them a good whisking.

Put the bowl over the simmering water and continue to whisk until the sugar is dissolved that the mixture is warm to the touch (no more than 120 degrees F).

Take the bowl off the simmering water and attach it to the mixer, onto which the paddle has been affixed. Beat on medium-high for roughly 8 minutes, until the mixture is extremely foamy. A thick ribbon should fall off the beater (I failed to capture it in this photo) and the small heaps of foam the falling ribbon creates should last for several seconds (I did manage to capture those).

Take about a cup of the foam and stir it into your melted (ideally clarified) butter. This will help the butter to more readily incorporate into the main volume of the batter.

Stir until it looks about like so (no need to be gentle):

And gently pour the mixture back into the mixer bowl...

...sprinkle in the flour and salt...

...and using your largest rubber scraper or spatula, fold until the mixture is uniform (instructions on how to fold properly are under the Techniques" menu to the right). 30 seconds or so later, your batter should look like this:

And there you have it: a génoise batter that you can use for a jelly roll, bûche de Noël, petits fours or a single nine-inch cake (instructions packaged separately).

I very much like the idea of using clarified butter in a génoise. It gives what is ordinarily a rather plain, somewhat dry sponge a toasty, homey quality that I really like. Of course if you don't have — or don't like making — clarified butter, regular melted butter will still produce a excellent result.

This recipe makes enough for one 18" x 13" sheet (a jelly roll, bûche de Noël, batch of petits fours) or one 9" cake. Here's the formula:

5 ounces (1 cup) all-purpose flour
4 tablespoons butter (preferably clarified)
½ teaspoon salt
6 eggs
7 ounces (1 cup) sugar
1 teaspoon vanilla extact

Preheat your oven to 350.

Set a saucepan big enough to hold your mixer bowl on the stove with an inch of water in it. Bring it to a simmer. Meanwhile, sift the flour and salt together into a medium bowl. Melt the butter in a small saucepan and set aside.

Pour the sugar into the mixer bowl, add the eggs and whisk to combine. Set the mixer bowl over the pan of water and heat the mixture until it’s warm to the touch (no more than 120 degrees). What you’re trying to do is simply melt the sugar...don't cook the eggs! It’ll only take a minute or so.

Remove the bowl from the heat and, using the paddle attachment, beat the mixture on medium high until it’s very light and foamy, about triple its original volume (this will take up to ten minutes with a stand mixer). Add the vanilla and beat an additional 10-15 seconds.

Pour a cup or so of the egg foam into the cooled melted butter and stir it until it’s completely incorporated, then gently pour the mixture back into the mixer bowl (this eases the incorporation of the butter into the batter). Next, sprinkle the flour mixture into the mixer bowl and carefully fold (instructions under the "Techniques" menu to the right) until the flour mixture and the butter mixture are completely incorporated. Gently pour the batter into the prepared pan.

Bake until the cake is a pale gold color and springs back lightly when touched.