9-inch pie shell, baked and cooled
1 c. sugar
3/4 c. butter, softened
1-1/2 tsp. vanilla
1/4 tsp. cream of tartar
3 sq. (1 oz. each) unsweetened chocolate, melted and cooled -or-
3 env. pre-melted, unsweetened chocolate
3 eggs
1 c. whipped whipping cream
2 tbsp. powdered sugar

Cream sugar and butter until fluffy. Beat in vanilla, cream of tartar and chocolate until well blended. Add eggs, one at a time, and beat until creamy and fluffy, about 3 minutes. Pour into a cooled pie shell and refrigerate for 4 hours or cover with plastic wrap and freeze for at least 8 hours.

Allow pie to sit at room temperature for about 15 minutes before serving.

For topping, whip the whipping cream and gradually add the powdered sugar until stiff. Garnish with nuts or chocolate if desired.