Preheat oven to 350 degrees and line an 8x8 pan with parchment paper. Lightly coat with a non-stick food safe spray.
In a blender or food processor, pulse Oreo cookies until fine, and add to a bowl with 1 stick of melted butter.
Put the crust into the base of the pan and flatten as evenly as possible, and chill in the fridge until the batter is complete. Note: Using a flat glass, or measuring cup works well.
In a large bowl beat 2 bricks of cream cheese until smooth. Then add ½ cup granulated sugar and 2 tablespoons of cornstarch and blend again.
Adding in 1 egg at a time, blend just until the deep yellow of the yolks are gone.
Pour in mashed banana, whipped cream and ½ tablespoon of pure vanilla, and beat one last time before adding to your pan.
Bake cheesecake at 350F for 15 minutes, then lower to 200F and bake for an additional hour. The cheesecake should only jiggle in the very middle if it does not add bake for longer starting in 5-minute increments.
Allow the cheesecake to cool completely. If any edges look tight after cooling, you can run a knife to loosen them. Chill in the fridge overnight or at least 8 hours.
Place on a cutting board and remove from pan, slicing into 16 squares!
To Store: You can store your cheesecake bars in the fridge for up to 5 days.
To Freeze: You can freeze these bars in a freezer bag for a few months.
To cut clean squares, it's helpful to run your knife under hot water and dry it with a paper towel before cutting the cheesecake into bars.
To bring cold eggs from the fridge to room temperature, let sit on kitchen counter for 1 hour (no longer than 2 hours).
When lining your pan with parchment paper, I recommend leaving the edges slightly higher than the pan to help lift the cheesecake out after cooling.