Crust
2 cups chocolate wafer crumbs
1/4 cup butter, melted

Filling
4 (1 ounce) squares unsweetened chocolate
1 1/4 cups butter, softened
1 1/3 cups granulated sugar
6 eggs
3 tablespoons cognac
2 cups finely chopped pecans
2 cups whipping cream, whipped
Chocolate curls

Combine chocolate wafer crumbs and 1/4 cup melted butter; stir well. Press mixture firmly on bottom and 1/2 inch up sides of a 10-inch springform pan. Bake at 350 degrees F for 10 minutes. Set crust aside, and let cool.

Place unsweetened chocolate in top of a double boiler. Bring water to a boil. Reduce heat to low; cook until chocolate melts, stirring occasionally. Set aside, and let cool.

Cream the 1 1/4 cups softened butter; gradually add sugar, beating well on medium speed of electric mixer. Add melted chocolate; blend well. Add eggs, one at a time, beating 3 minutes after each addition. Add cognac and pecans, stirring gently to combine. Pour mixture into prepared pan. Chill 3 hours.

To serve, carefully remove sides of springform pan. Garnish with whipped cream and chocolate curls.

Yields 10 to 12 servings.