For génoise
1/3 cup sifted unsweetened Dutch-process cocoa powder such as Droste (sift before measuring)
1/3 cup all-purpose flour
1/3 cup cornstarch
a pinch baking soda
3 large whole eggs
3 large egg yolks
2/3 cup sugar
1/4 teaspoon salt
For syrup
1/3 cup water
1/3 cup sugar
1/3 cup raspberry liqueur such as Chambord
For ganache
1 1/4 cups heavy cream
2 tablespoons unsalted butter
2 tablespoons light corn syrup
1 pound semisweet or bittersweet chocolate (not unsweetened),
chopped coarse
1/2 cup seedless raspberry jam
For glaze
1 cup heavy cream
8 ounces semisweet or bittersweet chocolate (not unsweetened), chopped coarse
Garnish: fresh raspberries
Make génoise:
Preheat oven to 350°F. Butter an 9-inch round cake pan (about 2 inches deep) and line
bottom with a round of parchment paper or foil.
In a small bowl whisk together cocoa powder, flour, cornstarch, and baking soda.
In a metal bowl whisk together whole eggs, yolk, sugar, and salt until combined. Set mixture
over a saucepan of simmering water and continue to whisk until lukewarm. Remove bowl from
heat and with an electric mixer beat mixture at high speed until it has cooled and doubled in
volume.
Sift one third cocoa mixture over egg mixture and fold in. Sift and fold in remaining cocoa
mixture, half at a time, in same manner. Pour batter into pan and smooth top. Bake génoise in
middle of oven for 30 minutes, or until it is firm to the touch and pulls away slightly from side of
pan. Invert génoise onto a rack and immediately invert onto another rack to cool right side up.
Génoise may be wrapped in plastic wrap and chilled 1 week or frozen 1 month. Thaw
génoise before assembling cake.
Make syrup:
In a small saucepan bring water and sugar to a boil over moderately low heat, stirring
occasionally until sugar is dissolved. Cool syrup and stir in liqueur. Syrup may be made 1
week ahead and chilled, covered.
Make ganache:
In a saucepan bring cream, butter, and corn syrup to a boil over moderate heat and remove
pan from heat. Add chocolate, swirling pan to submerge chocolate in hot mixture, and let
stand 3 minutes. Whisk ganache until smooth and transfer to a bowl. Chill ganache, covered,
at least 2 hours and up to 3 days.
Assemble cake:
Let ganache stand at room temperature until slightly softened and pliable but still cool. With a
whisk or electric mixer beat ganache just until light and fluffy.
Remove parchment paper from génoise and with a long serrated knife cut cake horizontally
into 3 rounds.
Invert top layer of génoise onto a spring form pan base or a 9-inch cardboard round and brush
with one third syrup. Spread layer with half of jam and spread one third ganache over jam.
Top ganache with middle layer of génoise and repeat layering of syrup, jam, and ganache.
Top with third layer of génoise, smooth-side up, and brush with remaining syrup. Spread top
and side of cake with remaining ganache. Chill cake until ganache is set, about 30 minutes.
Cake may be assembled ahead, wrapped in plastic wrap, and chilled 5 days or frozen 1
month. Thaw cake before proceeding.
Make glaze:
In a saucepan bring cream to a boil and remove pan from heat. Add chocolate, swirling pan
to submerge chocolate in hot cream, and let stand 2 minutes. Whisk glaze until smooth and
pour through a sieve set over a bowl. Cool glaze to room temperature.
With cake on a rack set over a pan (to catch drips) pour glaze through sieve onto center of
cake. Quickly spread glaze evenly over top and sides of cake with a long, narrow, metal
spatula. Let cake stand until glaze is set, about 5 minutes.
Garnish cake with raspberries and keep at cool room temperature until ready to serve.
