01 - Combine creamy peanut butter and powdered sugar in a medium bowl. Mix with a fork until mixture reaches crumbly consistency. Reserve for later use.
02 - Distribute half of the prepared peanut butter crumbs evenly across the bottom of the cooled pie crust. Press gently to create an even layer.
03 - Whisk together granulated sugar, all-purpose flour, and salt in a saucepan until thoroughly blended. Gradually incorporate whole milk while whisking to eliminate lumps.
04 - Place saucepan over medium heat. Stir continuously with whisk until mixture thickens and reaches a gentle boil, approximately 4-5 minutes.
05 - Whisk egg yolks in a separate bowl. Carefully ladle small amount of hot milk mixture into yolks while whisking constantly to prevent curdling.
06 - Return tempered egg mixture to saucepan. Continue cooking over medium heat for 2 minutes while whisking constantly until filling achieves thick, glossy consistency.
07 - Remove saucepan from heat. Stir in unsalted butter and vanilla extract until completely smooth and incorporated.
08 - Pour warm filling over peanut butter crumb layer in crust. Allow to cool at room temperature for 15 minutes, then refrigerate minimum 2 hours until completely set.
09 - Beat heavy whipping cream with powdered sugar and vanilla extract using electric mixer until stiff peaks form.
10 - Spread whipped cream over chilled pie surface. Sprinkle remaining peanut butter crumbs generously over top before slicing and serving.