Chocolate Oblivion

A friend let our school's cookbook use this recipe, but the school somehow left out part of the directions. I'm posting it here, so I'll always be able to find it. WARNING: Follow this recipe exactly or you will have problems with the cake. Pay attention to the cooling and chilling times; they are extremely important. There is no way to cut down the preparation time, but the end result is well worth the effort! Note: I've included chilling time in prep time.

• Ready In: 1 hr 30 mins
• Serves: 12
• Yields: 1 cake

Ingredients

• 2 1⁄2 teaspoons instant coffee or 2 1⁄2 teaspoons  espresso
• 2  cups cake flour
• 3 1⁄4 cups sugar, divided
• 3⁄4 cup  unsweetened cocoa
• 1 1⁄4 teaspoons baking soda
• 1⁄2 teaspoon baking powder
• 3⁄4 teaspoon salt
• 8  pasteurized eggs, divided
• 1  cup sour cream
• 1⁄2 cup  oil
• 2 1⁄2 teaspoons vanilla, divided
• 12  ounces  semisweet chocolate, divided
• 3  ounces  unsweetened chocolate
• 15  tablespoons butter, divided
• 1 1⁄2 cups heavy cream, divided

Directions

1. Heat oven to 350 degrees. Butter and flour two 9" round cake pans. Dissolve instant coffee or espresso in 1 cup hot water. Cool.
2. Combine flour, 2 cups sugar, cocoa, soda, baking powder and salt. Add coffee, 2 eggs, sour cream, oil and 1 teaspoon vanilla. Beat on medium speed for 2 minutes. Pour into pans. Bake until cake pulls away from side of pan, 25 to 30 minutes. Cool on rack 10 minutes. Remove from pans. Cool completely.
3. Chop 9 ounces semisweet chocolate and the unsweetened chocolate. Melt 12 tablespoons butter over low heat. Remove from heat and stir in the chopped chocolate until smooth. Separate the remaining 6 eggs.
4. Gradually beat 3/4 cup sugar into egg yolks. Slowly beat in 1 teaspoon vanilla and the chocolate mixture. Beat the egg whites separately with a pinch of salt until they hold soft peaks. Gently fold egg whites into the chocolate mixture. Beat 3/4 cup cream til stiff and fold into the chocolate mixture. Set aside 4 cups of this mousse mixture. Refrigerate remaining.
5. Cut the cakes in half horizontally to make 4 thin layers. Put two layers on separate plates. Spread each with 2 cups of the reserved mousse. Chill until firm, about 20 minutes (or freeze for 10 minutes). Top each with a second cake layer and refrigerate.
6. Beat remaining 3/4 cup of cream with 1/4 cup of sugar and 1/2 teaspoon vanilla until stiff. Spread over one of the layered cakes. Chill until firm, about 30 minutes. Top with second layered cake. Chill until firm, about 20 minutes.
7. Stir the remaining mousse to soften and spread over top and sides of cake. Melt the remaining 3 ounces semisweet chocolate with the remaining 3 tablespoons butter over low heat. Drizzle the melted chocolate over the top and around edge of the cake. Keep cake refrigerated.