Old-Fashioned Chocolate Pie
["1 1/4 c. plus 6 Tbsp. sugar", "1/2 c. cocoa", "1/3 c. cornstarch", "1/4 tsp. salt", "1 baked 9-inch pastry shell", "3 c. milk", "3 eggs, separated", "3 Tbsp. butter", "1 1/2 tsp. vanilla extract", "1/4 tsp. cream of tartar"]
["Combine 1 1/4 cups sugar, cocoa, cornstarch and salt in heavy saucepan.", "Whisk to remove lumps.", "Gradually whisk in milk.", "Cook over medium heat, stirring constantly, until thickened and comes to a boil.", "Boil 1 minute.", "Remove from heat.", "Beat the egg yolks until thick.", "Stir 1/4 of the hot mixture into the yolks.", "Add remaining yolks to hot mixture.", "Cook over medium heat for 2 minutes.", "Remove from heat and stir in the butter and vanilla."]
["sugar", "cocoa", "cornstarch", "salt", "pastry shell", "milk", "eggs", "butter", "vanilla extract", "cream of tartar"]