1 pie shell (8-inch), baked meringue or whipped cream, optional
Mix together cocoa, flour, and sugar in a double boiler. Add egg yolks and milk, and cook until thick, whisking frequently. Add butter and vanilla, heating until just melted and mixed. Cool. Pour into the baked pie shell and let set. If desired, top with meringue, browning lightly in a 325 degrees F oven for 15 minutes, or with whipped cream.