Combine sugar, cornstarch and salt in a saucepan. Gradually stir in milk and cook until thickened.
Remove from heat and continue stirring while adding the egg yolks. Return to heat and cook 2 minutes more.
Add butter and vanilla.
Pour hot custard into a bowl; cover and chill well.
Divide custard mixture into two bowls. Add peanut butter to one part and cocoa powder mix to the other. Whip each mixture until creamy.
Put peanut butter cream in the bottom of the pie shell and top with the chocolate mix.
Beat egg whites until stiff adding cream of tartar, sugar and vanilla to make meringue. Spread meringue on top of pie.
Bake in preheated oven at 350 degrees F. about 12 minutes or until meringue begins to brown.
Chill well before serving!