3 egg yolks
1 c. sugar
6 tbsp. flour
2 tbsp. cocoa
2 c. milk
1 tsp. vanilla
1 tbsp. butter

Combine in saucepan egg yolks, sugar, flour and cocoa. Add milk small amount at a time, mix well. Cook over medium heat until thickened and blended, stir while cooking. Cool and add vanilla and butter. Pour into baked pie shell. Top with meringue or Dream Whip.