Combine cream cheese, 1/4 cup sugar, vanilla and mix well until blended. Stir in 2 beaten egg yolks and melted chocolate pieces. Beat egg whites until soft peaks form. Gradually beat in 1/4 cup sugar. Fold into chocolate mixture. Whip the heavy cream and fold into mixture, then add pecans. Pour into crusts and freeze overnight.
Note: This recipe is for a large pie, so if you are using the smaller store-bought crusts, double the recipe and make 3 pies because this is enough filling for 1 1/2 of those crusts.