Mix in the sugar and peanut butter slowly, until mixture thickens.
Add milk and blend until smooth.
Fold in the Cool Whip until well incorporated.
Pour the mixture into two pie crusts and freeze until firm.
Video
Notes
Nutrition information is provided as an estimate only.
To Serve
Let pies thaw at room temperature for about 10 minutes before serving. For cleaner slices, dip your knife in hot water before cutting.
Pie Crust
Use any pie crust you like. A chocolate crust adds a fun peanut-butter-cup flavor.
Storage
This pie is great for making ahead. Store in the refrigerator for up to 1 week or freeze (without toppings) for up to 3 months, wrapped tightly in plastic wrap.