01 - In a medium bowl, mix together the creamy peanut butter and powdered sugar with a fork until crumbly. Set aside.
02 - Spread half of the peanut butter crumbs evenly in the bottom of the baked pie crust.
03 - In a saucepan, whisk together granulated sugar, flour, and salt until well blended. Gradually whisk in milk until smooth.
04 - Place saucepan over medium heat. Cook, whisking constantly until mixture thickens and just begins to bubble, about 4-5 minutes.
05 - In a separate bowl, whisk egg yolks. Gradually whisk in a small amount of the hot milk mixture to warm the eggs without scrambling them.
06 - Slowly pour the warmed egg mixture back into the saucepan, whisking constantly. Cook for 2 additional minutes until thick and glossy.
07 - Remove from heat. Stir in unsalted butter and vanilla extract until smooth and fully incorporated.
08 - Pour filling over peanut butter crumbs in pie shell. Cool 15 minutes at room temperature, then refrigerate at least 2 hours until completely set.
09 - Beat heavy cream, powdered sugar, and vanilla until stiff peaks form. Spread evenly over chilled pie.
10 - Sprinkle remaining peanut butter crumbs over whipped topping before serving.