1 c. chocolate wafer cookie crumbs (very fine)
1 tbsp. (or more) butter, melted
1/2 c. chopped nuts (any kind)

FILLING:

10 oz. semi-sweet chocolate
1/2 plus 1/2 c. whipping cream
1 tbsp. butter
1 1/2 lbs. cream cheese
1 1/4 c. sugar
6 lg. eggs
1 1/2 tsp. vanilla extract

To prepare chocolate: Melt chocolate over hot water, stirring while melting. Add 1/3 cup of whipping cream and 1 tablespoon butter. Mix well. Do not overcook. Set aside.

To prepare crust and pan for baking: Stir crumbs and butter together. Mix well. Butter bottom and sides of 9 inch spring-form pan. Press crumbs evenly over bottom of pan. Sprinkle with nuts. Drizzle 3 tablespoons of prepared chocolate over nuts. Place pan on 14 inch strip of heavy duty foil and fold to make a water-proof jacket about 2 inches up the sides of the pan. Place in a larger pan and fill larger pan 3/4 inch deep with water.

To prepare filling: Beat cream cheese and sugar until smooth. Beat in eggs, one at a time. Add 1/2 cup whipping cream and 1 teaspoon vanilla extract. Pour 3 cups of mixture into another container and add the remaining 1/2 teaspoon vanilla extract to it. Add reserved chocolate mixture to cream cheese mixture in the original bowl. Mix well. Pour all but 2 tablespoons of this chocolate mixture into prepared pan.

Carefully pour vanilla cheese mixture over chocolate layer, 1/2 cup at a time. Gently drop the reserved chocolate over the top of the cake. Swirl lightly with fingertip to create a marble effect.

Bake 2 to 2 1/4 hours at 300 degrees in a preheated oven. You can check if it's done by tilting batter. If it still moves, but there's no soupy puddle in center, it's done.

Remove from oven. Cool on wire rack to room temperature. Remove sides of pan. Chill to serve. Garnish with chocolate curls and whipped cream, if desired.