Beat the cream cheese, 1/3 cup of the peanut butter, powdered allulose, vanilla extract and salt with 1/4 cup of the heavy cream until smooth and creamy.
Whip the remaining heavy cream to stiff peaks in a separate bowl.
Fold the whipped cream into the peanut butter mixture in two additions until smooth and fluffy.
Fold in three quarters of the chopped peanut butter cups.
Warm the remaining peanut butter for 15 seconds in the microwave until pourable. Spread half the ice cream in a loaf pan, drizzle with half the peanut butter, then repeat with the remaining ice cream and peanut butter.
Swirl gently with a spoon handle and scatter the remaining peanut butter cups on top.
Cover and freeze for at least 6 hours. Let it soften for 10 minutes before scooping.