Freeze the bananas (with their skins on) for at least 24 hours. They should turn dark brown or black. Thaw them in a bowl in the refigerator for another 24 hours. Once they are thawed, poke a hole in one end of the banana peel and squeeze the innards out into a small bowl. (Mary's Note: "It will look pretty gross, but trust me, it tastes amazing!"

Stir the cream cheese and salt together in a large heat-proof bowl. Set aside.

Combine the cornstarch with 1/4 cup milk and set aside.

Combine the remaining milk, cream, sugar, and corn syrup in a sauce pan. Bring to a boil, then reduce to a simmer and cook for five minutes.

Remove the pan from heat, and add the banana mixture. Use an immersion blender to puree the banana completely into the custard. (You can also use a regular blender, but beware hot liquids.)

Whisk in the cornstarch mixture, and bring back the pan back to a boil. Reduce to a simmer, then cook for three minutes.

Slowly pour the mixture into the bowl with the cream cheese. Whisk continuously to make sure the cheese blends in evenly.

Add the vanilla, and mix well.

Cool the custard as quickly as possible. You can use an ice bath or transfer it to a large shallow dish. When the custard reaches room temperature move it into the fridge (covered) and let it chill for at least four hours. Chilling it overnight is ideal.

Churn the ice cream according to your machine’s directions. You want to churn the custard until it is very thick, and is pulling away from the sides of the barrel.

Set out the container (or containers) you plan to use to store the finished ice cream. Shake some cookie chunks, and place a dollop of Cool Whip into the bottom of each container. Now add a layer of ice cream, tapping it down to make sure it settles. Add another layer of cookie and another dollop of Cool Whip. Repeat until the container is full.

Freeze your packed ice cream for at least four hours before digging in.