Great Grandmother's Peanut Butter Pie

1 Deep Dish Pie Shell
3/4 cup sugar
3 T cornstarch
3 egg yolks
2 1/2 cups Evaporated Milk
1 t. vanilla
3/4 cup creamy peanut butter

Prepare pie shell. Combine sugar and cornstarch in a heavy 3 quart saucepan. Combine egg yolks and milk and gradually add to dry mixture, stirring well to prevent lumps. cook over medium heat, stirring constantly until thickened. Boil 1 minute. Remove from heat and stir in vanilla and peanut-butter. cool slightly then pour into cooled pie shell. Chill at least 3 hours.