In a microwave-safe bowl, combine creamy peanut butter and softened cream cheese. Microwave for about 20-30 seconds until slightly warm and easy to mix. Whisk until completely smooth.

Stir in the granulated sugar and salt, mixing until fully incorporated. Gradually add the heavy cream while whisking continuously, then add the whole milk and vanilla extract, whisking until smooth.

Pour the ice cream base into the Ninja Creami pint, seal tightly and place in the freezer for at least 24 hours until completely solid.

Remove the pint lid and insert it into the Ninja Creami. Select the 'ICE CREAM' program and process until creamy and smooth.

Create a hole in the processed ice cream and add the chopped mini peanut butter cups. Run the 'MIX-IN' cycle to distribute the chunks.

Serve immediately for soft-serve or transfer back to the freezer for 1-2 hours for firmer consistency.