Beat the egg yolks with an electric mixer until thick and lemon colored.
sugar and cornstarch in a small bowl. Add to egg yolks and beat until creamy. Stir
in milk and peanut butter.
Transfer to top of double boiler or saucepan. Cook over
low heat, stirring constantly until the pudding has thickened and the peanut butter
has blended into the mixture. Stir in vanilla extract.
Pour into the pie shell.
Meringue: Beat the egg whites and water with an electric mixer on medium speed
until foamy. Add cream of tartar and beat on high speed until soft peaks form. Gradually
adding sugar, continue to beat until stiff peaks form.
Spread meringue over filling,
making sure to spread slightly onto crimped edge of pie crust to seal filling.
Bake at 350 degrees F for 10 to 12 minutes or until meringue is light brown.