In a large mixing bowl, whip your heavy cream over medium high speed for about 5 minutes until stiff peaks start to form. (It may take longer or shorter depending how fast you're doing it, you want it stiff, but a few minutes too long and you'll turn it into butter)

In another bowl, combine your condensed milk and cocoa powder.

Pour your whipped cream into your chocolate condensed milk mixture and fold everything together till combined.

Melt your peanut butter in the microwave for about 30 seconds.

Pour one third of your ice cream into a 9x5in loaf pan. Drizzle one third of your peanut butter over the ice cream and sprinkle with a third of the peanut butter cup pieces. Repeat with another third ice cream, peanut butter and peanut butter cups. And then repeat with the final ice cream, peanut butter and peanut butter cup pieces.

Cover tightly and place in freezer for 6 hours, up to overnight.