Cake
1 cup hazelnuts
10 egg whites (or 1 1/2 cups) at room temperature
3/4 cup sugar
1/4 cup flour
1. Preheat oven to 300 degrees.
2. Spread hazelnuts on baking sheet and roast 5 to 10 minutes, until they are fragrant and lightly browned. Cool, then pulverize to medium-fine powder in blender or food processor.
3. Heavily butter two 10-by-14-by-1-inch baking sheets and line with parchment paper. Butter and flour paper.
4. Beat egg whites in a mixer, adding sugar gradually, just until stiff. Fold in flour and powdered hazelnuts. Divide mixture in half, spreading evenly on baking sheets. Bake 20 minutes in 300-degree oven, or just until cakes begin to brown. Remove from oven, turn onto rack, paper side up. Cover with damp towel for several minutes, then carefully remove paper while cake is still warm. Cut cakes in half length-wise. Yield: Four 14-by-5-inch layers.
Chocolate cream
2 cups crême fraiche (see recipe below)
15 ounces (or five 3-ounce bars) extra bittersweet chocolate (the recipe calls for Lindt brand; I used Ghiradelli)
Bring crême fraiche to a boil. Remove from heat and add chocolate, bit by bit, stirring until well incorporated. Set aside until cool and thickened. It should have the consistency of thick but spreadable frosting. This can be made as much as 3 days in advance and refrigerated. If it hardens, reheat gently, beating until it reaches proper consistency. Yield: 3 cups.
Crême Fraiche
1 cup sour cream
1 cup heavy sweet cream
Pour sour cream into bowl and gradually stir in sweet cream until smoothly blended. Cover and allow to sit at room temperature for 8 to 12 hours. Stir again and refrigerate for 24 hours before using. Yield: 2 cups.
Pastry Cream
8 egg yolks
1 cup sugar
1/2 cup flour
2 1/2 cups milk
10 ounces butter, at room temperature
1. Beat egg yolks with sugar until thick and light. Incorporate flour. Bring milk just to boil in a large, heavy-bottomed pan. Whisk half hot milk into egg mixture, then pour egg and milk mixture back into pan containing other half of milk. Whisk over medium heat until thick and boiling. Let boil lightly for 2 minutes, whisking constantly until thickened.
2. While mixture cools, work butter in large bowl with wooden spoon, beating until creamy and spreadable. When mixture is completely cool, dot pastry cream with butter, then beat thoroughly until incorporated. This can also be made 3 days in advance and refrigerated. Yield: 4 cups pastry cream.
Praline Powder
1 cup whole, unblanched almonds
1 cup powdered sugar
vegetable oil
1. Preheat oven to 300 degrees.
2. Spread almonds on baking sheet and roast 5 to 10 minutes, until nuts are fragrant and lightly browned. Cool.
3. Oil the cool baking sheet with tasteless vegetable oil.
4. In a heavy-bottomed pan, combine nuts and sugar and heat gently, stirring constantly, until sugar starts to melt. Mixture will go through many stages, from dry blend to one where sugar forms balls the size of peas. Continue cooking, stirring constantly, until mixture turns dark brown and syrupy and nuts make popping sound. Whole process will take about 5 minutes.
5. Pour mixture onto oiled baking sheet and cool. You have, essentially, almond brittle. When cool, break into pieces and blend to fine powder in blender or food processor. Praline can be made weeks in advance and refrigerated or frozen in airtight container. Yield: 1 1/2 cups praline powder.
Assemble the marjolaine at least 1 day and not more than 5 days before serving:
1. Divide pastry cream into 2 equal parts.
2. Prepare run cream and praline cream.
Rum Cream
2 cups pastry cream
1 tablespoon vanilla extract
3 tablespoons rum
Blend vanilla and rum into cream. Set aside.
Praline Cream
2 cups pastry cream
1 1/2 cups praline powder
Blend cream and praline just before assembling cake (otherwise flavor will fade).
Final assembly:
1. Be sure chocolate cream and pastry cream are chilled but spreadable. Place 1 layer of cake on large rectangular serving platter. Spread half chocolate cream on cake. Refrigerate 15 minutes to firm up.
2. Cover chocolate cream with second cake layer. Spread with all praline cream. Refrigerate 15 minutes.
3. Top praline layer with fourth cake layer. Frost top and sides of cake with remaining half of chocolate cream. Refrigerate uncovered for 15 minutes, then cover with plastic wrap. Keep refrigerated for 1 to 5 days before serving. To serve, remove from refrigerator 30 minutes to an hour before serving. Cut from narrow end into thin slices. Yield: 16 to 20 servings.
