Chocolate Cream Pie

1 cup sugar

½ cup cornstarch

3/8 cup cocoa

1/8+ tsp salt

4 egg yolks, beaten

4 cups milk

2 T butter

2 tsp vanilla

¾ whipping cream

1/3 cup sifted powered sugar

Combine sugar, cornstarch, cocoa and salt and in a heavy saucepan; stir well. Combine egg yolks and milk; gradually stir into sugar mixture. Cook over medium heat, stir constantly, until mixture thickens and boils. Boil 1 minute, stirring constantly. Remove from heat; stir in butter and vanilla. Immediately pour into pastry shell. Cover filling with plastic wrap. Let cool 30 minutes; then chill until firm.