Chocolate Mousse Cake II

Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 9 inch springform pan, or use parchment paper liner. In a large bowl, mix flour, 1 cup sugar, cocoa and 1/4 teaspoon salt. Make a well in the center and add the coffee, oil, 1 tablespoon vanilla and egg. Beat until combined, batter will be thin. Pour into springform pan. Bake at 350 degrees F (175 degrees C) for 30 to 45 minutes, or until toothpick inserted into cake comes out clean. When cake is completely cool, remove from pan, cut top of cake level with a knife, and place back into springform pan. To make the mousse: Melt 16 ounces chocolate and 1/2 cup butter over double boiler, stir in 1/4 teaspoon salt and 2 teaspoons vanilla, whisk in yolks. In a separate bowl, beat whites until foamy, gradually add sugar, and continue beating until stiff. Fold into chocolate mixture. Whip the 1 1/2 cup cream in a separate bowl and fold into chocolate mixture. Pour over leveled cake in springform pan and set for 1 to 2 days. To make the Chocolate Ganache: Chop the 4 ounces of semisweet chocolate. In the top of a double boiler, heat chocolate and 1/4 cup cream, stirring occasionally, until melted and smooth. When the cake is completely set, remove from pan and drizzle ganache over the top. Using your hand, gently press chopped nuts into the side of the mousse.