For the smoothest and most stable filling, use regular creamy peanut butter instead of natural peanut butter, as natural varieties can separate and prevent the pie from setting properly. Make sure the cream cheese is fully softened before mixing to avoid lumps and create a silky texture. For the cleanest slices, chill the pie for at least 6 hours, although overnight is recommended for the best results. Store any leftovers covered in the refrigerator for up to 5 days or freeze for up to 2 months. Thaw frozen slices overnight in the refrigerator before serving.