1 c. sugar
1/3 c. flour (self-rising) or 3 tbsp. cornstarch
3 tbsp. cocoa
1/8 tsp. salt
2 c. milk
3 slightly beaten egg yolks
2 tbsp. butter
1 tsp. vanilla

In saucepan, combine and sift sugar, flour, cocoa and salt. Mix well. Gradually stir in milk. Cook in double boiler over boiling water, stirring constantly until mixture begins to thicken. Put on top and cook for 15 minutes. Remove top and stir small amount of hot mixture into yolks. Return to hot mixture. Cook 2 minutes more, stirring constantly. Remove from heat. Add butter and vanilla. Cool to room temperature. Pour into baked pastry shell.