In a large mixing bowl, whisk together the heavy cream, whole milk, granulated sugar, and salt until the sugar dissolves completely.
Add the creamy peanut butter and vanilla extract and mix until smooth.
Gently fold in the marshmallow fluff until evenly distributed.
Cover and chill the mixture in the refrigerator for at least 2 hours.
Pour the chilled mixture into an ice cream maker and churn according to the manufacturer's instructions (about 20-30 minutes).
During the last few minutes of churning, add the white chocolate chips.
Transfer to a storage container, cover tightly, and freeze for at least 4 hours until firm.