Okay, so maybe the sponge cake isn't literally an American invention (most food historians agree that the sponge cake as we now know it was probably a European recipe created in the early 19th century), but it feels American to me: sturdy, dependable, versatile, basic. An egg-and-sugar canvas for a multitude of flavorings and cultural influences. I also hear that sponge cake opposes the war. But that's another post.
Sponge cake is basically an angel food cake made with whole eggs instead of egg whites. There are a few variations, but sponge cake recipes are always low on ingredients and high on technique. When done right it tastes of fresh, pillowy, just-eggy-enough French toast, and the interior looks delightfully like its namesake:
When done wrong, it looks like flat, day-old French toast and tastes like its namesake. You see what I'm saying here.
Remember that sponge cake batter does best when it's like Santa Monica summer: warm and breezy. With a sponge cake, it's really all about the eggs. They provide the sturdy structure, effervescent interior, and most of the lift in this cake. In general, all baking goes much smoother with room temperature eggs, but in a cake like this, air will find it's way much more swiftly and certainly into both the whites and the yolks when they have had a chance to warm up out of the fridge. Since my baking urges hit suddenly and strongly, and are rarely premeditated, I've discovered that bathing the eggs in warm water while I set everything else up does a nice job of bringing them up to a more batter-friendly temperature quickly.
I also opted to turn the following recipe into a hot-milk sponge cake, which was recommended in several recipes I found, and heated the milk in the microwave for one minute (opting to add some good vanilla to it) to keep the Santa Monica summer thing happening in the batter (I haven't been to culinary school, but I'm sure this isn't a technical term).
This recipe calls for baking all of the batter in one glorious, thick layer in a 9-inch springform pan, which I also think makes it so versatile. Among other things, you can tear the finished sponge cake into chunks for a berry trifle, douse it with something delicious to celebrate its literal sponginess (more on that in the coming days), or slice it into two or three layers to fill it (Boston Cream Pie, anyone?). However, you can easily divide the batter into two cake pans--just reduce the cooking time to 16-20 minutes. This cake also freezes beautifully for future endeavors, like when you unexpectedly find yourself with some really good ice cream...or something.
You can avoid the depressing, sinking center that sponge cakes tend to have by working quickly when it comes out of the oven, loosening the edges with a thin knife and immediately turning it out of the hot pan and cooling it right side up on a rack. This one cooled as tall and as proud as it first looked coming out of the oven:
For this sponge cake go around, I opted to simply slice it across, fill it with homemade strawberry jam, and have a hunk out on the porch with a glass of ice-cold milk. I am, of course, an American girl.
Classic Sponge Cake
Enjoy plain or with various fruits, glazed, soaked, filled with ice cream, mousse, jam...you have the right to freedom of sponge cake. And that's just straight up American.
1 cup granulated sugar
5 egg yolks
5 egg whites
1/3 cup milk
1 teaspoon vanilla extract
1 cup all-purpose flour
1 1/2 teaspoons baking powder
1/4 teaspoon salt
Preheat oven to 350 degrees. Wrap the bottom of a 9-inch springform pan with parchment then lock it into place, and butter the pan and the parchment.
Heat 1/3 cup milk in the microwave for one minute, stir in vanilla, set aside.
Whisk together flour, baking powder and salt, set aside.
In a stand mixer with a paddle attachment or with an electric hand mixer, beat the egg yolks with 3/4 cup sugar until light in color and doubled in volume. They will be a beautiful, creamy pale yellow color, like the walls of my apartment.
Set the mixer on low and stir in the milk mixture first and then the flour mixture, scraping the bowl as necessary, and then set aside.
In a small, grease-free bowl, beat the egg whites with an electric hand mixer or in a clean stand mixer bowl with a whisk attachment. When soft peaks form, gradually rain in the remaining 1/4 cup sugar. Beat until firm but not dry.
Fold 1/3 of the egg whites into the yolk mixture first, to lighten it up. When mostly combined, add the remaining 2/3 of the whites and continue to fold carefully, through the center of the batter, under it and back over to keep as much air in the mixture as possible. When the egg mixtures are fully incorporated, pour batter into the prepared pan.
Bake at 350 degrees for 45 to 50 minutes or until a cake tester comes out clean. It will be a gorgeous, light brown color. Immediately place the cake on a rack, remove the springform ring and remove the cake from the pan bottom by lifting off the parchment paper. Cool the cake completely on a rack, then remove the paper before placing on a serving platter.