Recipe: Génoise (Whole Egg Sponge Cake)

A good Génoise cake is going to rise a lot in baking, enough that you can make two or three layers by slicing a single cake. It will be 3 or 4 inches tall. This means that you need a pretty deep cake pan to make it, like the deep aluminum pans you'll find in kitchen supply stores that have the sorts of heavy but inexpensive equipment used in restaurant kitchens. You also need a thermometer that you are confident is both accurate to within 2 or 3 degrees and that you can read that precisely.

	6-Inch Cake	8-Inch Cake
Eggs	3	5
Sugar	1/3 cup (75 grams)	1/2 cup (125 g)
Cake flour, sifted	1/2 cup (75 grams)	7/8 cup (125 grams)

Prepare one cake pan (choose a deep pan, at least 2" tall) by buttering and flouring it, line the bottom with parchment paper, and put it in the refrigerator to cool. Preheat the oven to 350F.

It is better to weigh your ingredients if possible, especially the flour, but since many home cooks do not have a scale, I've approximated the equivalent volume measurements.

Get a double-boiler ready by fitting a large bowl (large enough to be able to vigorously whisk the eggs until they triple in volume) over a hot water bath. Do not let the water touch the bottom of the bowl. Once you've checked that the bowl fits over your pan and that the water does not come to the bottom of the bowl, set the bowl aside (it must not be hot when you add the raw eggs to it) and heat the water to a simmer.

Put the eggs and sugar into your bowl and begin whisking them with a large balloon whisk. After they come together (about a minute), continue whisking over the hot water bath. Whisk until the eggs are tripled in volume, which will take about 10 minutes (or more like 30 minutes if you are stirring and not whisking, something that as simple as it sounds I did not really understand until Chef Marc yelled at me about 10 times over the course of 20 minutes on the night we first made Hollandaise sauce -- to whisk, you have to rapidly lift the whisk completely out of the egg mixture with each stroke so that you pick up a lot of air). While you whisk, periodically check the temperature of the mix. If you reach 115F, take it off the heat. You must get to at least 110F, 115F is ideal, and if at any point the eggs go over 120F you should throw them away and start over. When you take the temperature, tip the bowl up on its side and lay the thermometer in it along the side of the bowl so that you have a couple inches of the thermometer in the eggs. If you reach the proper temperature before the eggs have been whisked until light and foamy and 3 or 4 times their original volume, take the bowl off the heat to finish whisking.

Fold in the sifted flour with a spatula, trying not to stir too much and deflate the batter. Pour the batter into the buttered and floured cake pan. Spin the pan around quickly one time and bang it firmly on the countertop one time to even out the batter. Place it in the oven and bake until the cake does not keep an indentation you make in its top with your finger. Wait at least 20 minutes before you open the oven door to check it for the first time. The cake will get quite brown before it is finished. My cakes have all taken 35-40 minutes to bake. If the cake is not completely baked, it will collapse when removed from the oven.

When it is finished, remove it from the pan immediately and let it cool on a cooling rack, covered with a damp towel to keep it from drying out. Once it dries, the cake is usually sliced in half (into layers) and middle of the cake is brushed with a simple syrup (a mix of equal parts sugar and water, heated to dissolve the sugar, which you can also flavor with things like whole cloves or cinnamon sticks that you remove before you use the syrup). The cake can absorb a lot of syrup without getting soggy -- I used about 1/2 cup of syrup on one 6-inch cake. You can frost between the layers or not, as you like.