1 (9 oz.) baked pastry shell (or crumb crust, see below)
1/3 c. Hershey's cocoa
1 1/4 c. granulated sugar
1/3 c. cornstarch
1/4 tsp. salt
3 c. milk
3 tbsp. butter
1 1/2 tsp. vanilla
Sweetened whipped cream or non-dairy whipped topping (optional)

Prepare pie shell; set aside. Combine cocoa, sugar, cornstarch, and salt in a medium saucepan. Blend in milk until smooth. Cook and stir over medium heat until mixture comes to a boil. Boil and stir for 3 minutes. Remove from heat. Blend in butter and vanilla. Pour into pie shell. Chill 3 to 4 hours. Serve with sweetened whipped cream or whipped topping.

CHOCOLATE CRUMB CRUST:

1 1/2 c. vanilla wafer crumbs
6 tbsp. Hershey's cocoa
1/3 c. confectioners' sugar
6 tbsp. butter, melted

Combine crumbs, cocoa and sugar in a bowl. Stir in butter. Press mixture onto bottom and sides of a 9-inch pie plate. Bake at 350 degrees for 8 to 10 minutes. Cool.