01 - Mix creamy peanut butter and powdered sugar in a medium bowl using a fork until crumbly texture forms. Set aside for later use.
02 - Spread half of the prepared peanut butter crumbs evenly across the bottom of the cooled baked pie crust.
03 - Whisk together granulated sugar, all-purpose flour, and salt in a saucepan until thoroughly blended.
04 - Gradually whisk whole milk into the dry mixture, ensuring no lumps remain until completely smooth.
05 - Place saucepan over medium heat. Cook while whisking constantly until mixture thickens and just begins to bubble, approximately 4-5 minutes.
06 - Whisk egg yolks in a separate bowl. Gradually incorporate small amounts of the hot milk mixture while whisking to gently warm the eggs without curdling.
07 - Pour tempered egg mixture back into the saucepan while whisking continuously. Cook for 2 additional minutes until mixture achieves thick, glossy consistency.
08 - Remove from heat. Stir in unsalted butter and vanilla extract until butter melts completely and mixture is smooth.
09 - Pour warm filling over the peanut butter crumbs in the pie shell. Let cool at room temperature for 15 minutes, then refrigerate for minimum 2 hours until fully set.
10 - Beat heavy whipping cream with powdered sugar and vanilla extract using electric mixer until stiff peaks form.
11 - Spread whipped cream evenly over chilled pie surface. Sprinkle remaining peanut butter crumbs generously over top before serving.