Beat the peanut butter and half of the sweetened condensed milk together with the whisk attachment until it is blended and cream. Slowly add the remaining sweetened condensed milk until it is completely incorporated.
Pour in the heavy cream and beat until soft peaks form.
Pour in a small amount of the mixture into a 9x5 loaf pan. Drizzle with some of the fudge sauce and some of the peanut butter cups. Repeat the layers until all the ice cream is used. Freeze until firm.
Notes
Store in an airtight container in the freezer for up to a month