Grandmother Ray'S Chocolate Pie
["1 1/2 c. sugar", "2 Tbsp. cocoa", "1/4 c. cornstarch", "3 c. milk (Carnation and regular)", "4 egg yolks", "1 Tbsp. butter", "1 tsp. vanilla"]
["Mix the first 5 ingredients; cook over medium heat until very thick.", "Add the butter and vanilla.", "Let set 5 minutes.", "Pour into baked pie shell."]
["sugar", "cocoa", "cornstarch", "milk", "egg yolks", "butter", "vanilla"]