Before starting the cream mixture, put an empty 9x9 metal pan into the freezer. Freeze for at least 30 minutes. (If you forget to do this, just put the bowl with the cream mixture into the refrigerator while you chill the pan.)
Once the pan is frozen pour the cream mixture into the pan and carefully place in the freezer.
After 20 minutes, stir the mixture and be sure to get all the edges mixed into the middle.
Return the pan to the freezer for 30 minutes then stir again.
Continue stirring every 30 minutes until you have a frozen creamy mixture.
Proceed with putting the ice cream between the cookies. Then freeze for at least 4 hours or up to 3 days.