Chocolate Sponge Cake

I've made this cake for visitors three times in the past 6 weeks or so, and all of my guests have been suitably impressed (or they were very gracious guests/good liars). And yet it's really quite simple. With only 6 ingredients that I'm sure you have in the cupboard, you could go make it right now if you wanted to. Well, except for the parchment paper. Using parchment paper is pretty much a necessity with this cake. I suppose you could try it with aluminum foil, but I don't really recommend it. Go get some parchment paper and then make this cake and fill it with almost anything: ganache, raspberry jam, chopped strawberries, lemon curd? (I've been thinking about trying that one. Thoughts?), cream cheese frosting (or a mascarpone icing, which I did once and it was fabulous), powdered sugar...let me know if you have any other ideas.

Now. As you assemble this cake, you can be a perfectionist and get our your ruler and make sure you cut the three pieces into perfectly even sizes. Or you can be like me and guesstimate and end up with the smallest piece on bottom (oops) which you cover up by shoving ganache in the space. It won't matter in the end. But do make sure you eat the trimmings while you assemble. And definitely lick the pan in which you made the ganache. It will make your day just a bit brighter. 

Chocolate Sponge Cake
Recipe adapted just a teensy bit from Bon Appetit March 2012
Pictures by Kelly

Cake:
1 tablespoon unsalted butter, room temperature
1/4 cup unsweetened cocoa, plus about a tablespoon for dusting
1/4 cup cake flour (all purpose will also work)
4 large eggs, at room temperature
1/2 cup plus 6 teaspoons sugar
1 teaspoon vanilla

1. Preheat oven to 400 degrees F. line the bottom of a 9 x 13 inch pan with parchment paper. Butter paper and sides of pan; dust with cocoa powder, tapping out excess. Sift flour and remaining 1/4 cup cocoa powder through a fine-mesh sieve into a small bowl. Repeat sifting 2 more times. Set flour mixture aside. 
2. Crack 2 eggs into a large deep bowl. Separate remaining 2 eggs, adding yolks to bowl with whole eggs and placing whites in a medium deep bowl. Set whites aside.
3. Using an electric mixer, beat whole eggs and yolks on low speed for 1 minute. Increase speed to medium; gradually add 1/2 cup sugar. Beat until mixture is thick and pale, about 3 minutes. Beat in vanilla.
4. Using clean, dry beaters, beat egg whites until foamy. Sprinkle 1 teaspoon sugar over. Continue to beat until soft peaks form, about 1 minute. Sprinkle remaining 5 teaspoons sugar over and beat until meringue is thick and glossy, about 30 seconds.
5. Using a rubber spatula, fold half of meringue into egg mixture. Sift half of dry ingredients over batter and fold until just blended. Repeat with remaining meringue and dry ingredients. Scrape batter into prepared pan, spreading evenly to edges. Bake until cake springs back when pressed gently with your fingertips, 10-12 minutes. Let cake cool in pan on a wire rack. Run a knife around sides of pan to release cake.
6. Place a cutting board on top of pan. Invert cake onto board; remove pan. Carefully peel away parchment. Using a serrated knife, trim edges to create an even layer and cut into 3 equal pieces. Cover each piece with icing and stack the layers.  

Chocolate Icing:
3/4 cup heavy cream
1 cup semisweet or bittersweet chocolate chips

1. Bring cream to a simmer in asmall saucepan over medium low heat. Remove from heat; add chocolate chips and stir until icing is smooth and flossy. Let cool to thicken slightly, about 15 minutes.