1 (8-inch) baked pastry shell
1/2 cup butter
3/4 cup granulated sugar
1 (1 ounce) square unsweetened chocolate
1/2 teaspoon vanilla extract
2 eggs

Melt chocolate and let cool.

Cream butter; add sugar gradually, creaming well. Blend in cooled, melted chocolate. Add vanilla extract. Add eggs, one at a time, beating 5 MINUTES after each addition. Turn filling into cooled shell. Chill pie in freezer for 10 minutes, then in the refrigerator for 1 to 2 hours before serving.

If desired, serve garnished with whipped cream and chopped nuts.