01 - In a medium bowl, whisk together heavy cream, whole milk, sugar, salt, and vanilla extract until the sugar is completely dissolved.
02 - Pour the mixture into an ice cream maker and churn according to manufacturer's instructions, about 20-25 minutes, until thick and creamy.
03 - While the ice cream churns, combine cream, chocolate chips, butter, corn syrup, and salt in a small saucepan over low heat. Stir continuously until melted and smooth. Let cool to room temperature.
04 - Once the ice cream is churned, gently fold in the halved peanut butter cups until evenly distributed.
05 - Spoon one-third of the ice cream into a freezer-safe container. Drizzle with one-third of the fudge sauce. Repeat layers twice more with remaining ice cream and fudge. Gently swirl with a knife for a marbled effect.
06 - Cover and freeze for at least 6 hours, or until firm enough to scoop.
07 - Scoop into bowls or cones and serve immediately.