For torte, grease bottom and side of a 10-inch springform pan; set aside.

In heavy, large saucepan, combine the 16 ounces chocolate, the butter, sugar, 1 cup whipping cream, and salt, if using. Cook over medium-low heat until chocolate and butter are melted; stir frequently. Remove from heat.

In a large bowl, whisk eggs and vanilla together. Slowly stir half of the chocolate mixture into eggs. Return egg mixture to remaining chocolate mixture, stirring until combined.

Pour batter into prepared springform pan, placed on a foil-lined baking sheet. Bake in a 350 degree F oven for 45 to 50 minutes or until evenly puffed and a knife inserted near center comes out clean. Remove from oven; cool thoroughly on a wire rack. Chill in the refrigerator about 4 hours or until firm.

For ganache, in a small saucepan, heat 1 cup whipping cream to just boiling. Place the 12 ounces chocolate in a medium bowl. Add hot whipping cream. Stir until chocolate is melted and smooth. Cool to room temperature.

Set torte on serving plate. With a knife or narrow metal spatula, carefully loosen cake and remove side of pan. Spread ganache over top of torte, allowing some of the ganache to drizzle down sides. Cover and chill in the refrigerator for several minutes or until ganache is set.

If you like, pipe or drizzle stripes or other designs on the torte with melted white chocolate. For easier eating, let the torte stand at room temperature about 30 minutes before slicing it. Makes 20 servings.

Omit salt if using regular butter.