2In bowl, mix peanut butter and powdered sugar until crumbly. If it's sticky, add powdered sugar 1 tablespoon at a time until it turns crumbly.
Reserve 1/4 cup of crumb mixture.
Sprinkle remainder of crumbs in the bottom of pre baked pie shell.
In a medeium saucepan combine 1/2 cup granulated sugar, cornstarch, and salt. Stir in milk and 3 egg yolks until well mixed. Cook and stir over medium heat until mixture comes to a boil. Boil 1 minute, remove from heat, add vanilla and set mixture aside.
In large bowl beat the 3 egg whites and cream of tartar with an electric mixer on medium speed. Gradually add 6 tablespoons of granulated sugar, 1 tablespoon at a time, beating on high speed to stiff peaks.
5Pour filling onto pastry shell over peanut butter layer. Spread meringue over top and seal to pastry. Sprinkle with reserved peanut butter crumbs.
Bake for 15 minutes. Cool pie for 1 hour and refrigerate. Chill for 3 hours. Serve...