Chocolate Pyramid Cake -- Nathan's Cookbook

Chocolate Pyramid Cake

A tiered extravaganza: triangular chocolate cake layers filled with chocolate mousse and raspberries and spread with a creamy chocolate ganache. Edible gold leaf, more raspberries and piped ganache top it off in style. You can begin preparations up to two days ahead. 40 servings.

Cake

2 cups warm water
2 tablespoons instant espresso powder
3 cups sifted cake flour
2/3 cup plus 4 teaspoons sifted unsweetened cocoa powder
2 teaspoons baking soda
1 teaspoon salt
1/2 teaspoon (generous) baking powder
1 cup (2 sticks) butter, room temperature
3 cups sugar
4 large eggs, room temperature
2 ounces unsweetened chocolate, chopped, melted, cooled to barely lukewarm

Preheat oven to 325ºF Butter 2 heavy straight-sided 18xl2xl-inch baking pans. Line with parchment. Butter and flour parchment. Pour water into medium bowl. Add espresso powder and stir to dissolve. Cool completely. Sift flour, cocoa, baking soda, salt and baking powder into another medium bowl. Using electric mixer, cream butter in large bowl until light. Gradually add sugar and beat until fluffy. Add eggs I at a time and beat until just combined. Add melted chocolate and beat until just blended. Mix dry ingredients and espresso liquid alternately into batter, beginning and ending with dry ingredients.

Divide batter evenly between prepared pans. Bake until tester inserted in center of cakes comes out clean, about 20 minutes. Cool cakes in pans on racks. Cover pans with aluminum foil and refrigerate cakes overnight. (It is important that cakes be well chilled for easy handling during assembly.)

Mousse

1 pound bittersweet (not unsweetened) or semisweet chocolate (such as Baker's), chopped
11 tablespoons butter
7 large egg yolks
1/2 cup sugar
3/4 cup plus 3 tablespoons chilled whipping cream
3 large egg whites, room temperature
3/4 cup plus 3 tablespoons sour cream, whisked until smooth

Place chocolate and butter in medium bowl. Set bowl over saucepan of simmering water and stir chocolate mixture until smooth and melted. Remove from over water and cool.

Whisk yolks and sugar in large bowl. Set bowl over saucepan of simmering water and whisk until just warm to touch, about 3 minutes. Remove from over water. Using electric mixer, beat until mixture whitens and triples in volume. Whip cream in medium bowl to soft peaks. Using clean dry beaters, beat whites in another medium bowl to soft peaks. Using clean dry beaters, beat whites in another medium bowl to soft peaks. Whisk chocolate into yolk mixture. Fold in sour cream. Fold in whipped cream in 2 batches. Fold in egg whites in 2 batches. Cover and refrigerate mousse overnight.

Ganache

4 pounds 9 ounces bittersweet (not unsweetened) or semisweet chocolate (such as Baker's), finely chopped
3/4 cup plus 1 tablespoon light corn syrup
3/4 cup plus 1 tablespoon brandy
5 3/4 cups plus 1 tablespoon whipping cream

Combine chocolate, corn syrup and brandy in large bowl. Bring cream to boil in heavy large saucepan. Pour over chocolate mixture. Stir until chocolate is melted and smooth, placing bowl over large saucepan of simmering water if necessary to melt chocolate completely. Cover and let stand until cool and spreadable, about 4 hours. (Can be prepared 1 day ahead. Cover and let stand at room temperature.)