Preheat the oven to 325 degrees and grease a 9 inch springform pan. You will need a large roasting pan that’s bigger and longer than the springform pan. (I use the aluminum foil disposable ones). If you are not sure about your springform holding up in water, you can wrap the outside of the springform pan in heavy duty aluminum foil from bottom up to the sides. (I recommend wrapping the outside of the springform in foil before adding the crust and cheesecake batter.)
Pulse cookies in the blender until it becomes just crumbs.
In a small bowl, combine cookie crumbs and melted butter until evenly incorporated.
Press cookie crust mixture into the pan, evenly, all over the bottom and a little bit up the side.
Start beating cream cheese and sugar on medium-high speed until smooth, about 2 minutes.
Add mint extract, and sour cream. Mix until combined.
Add eggs, one at the time, beating after each addition. Scrape sides and bottom of the bowl and beat until all incorporated.
Lower speed and add corn starch. While on medium low speed, pour in heavy cream. Mix until all combined, scrape the sides and bottom of the bowl and mix again until smooth.
Stir in chocolate chips.
Pour the cheesecake batter into the spring form with prepared crust.
Place roasting pan into the oven and place the cheesecake springform pan inside the roasting pan. Carefully add water to the roasting pan, about half way up the side of the springform.
Bake for 70-75 minutes. Turn off the oven and open the oven door half way. Let cheesecake rest for about 10 minutes and take it out of the oven (out of the roasting pan and carefully take off the foil).
Let it rest for 20 minutes on the counter and then gently run a greased butter knife between sides of the cheesecakes and the springform to carefully separate it. (You don't actually have to take the cheesecake out of the pan until ready to add topping.)
Cool cheesecake for about an hour and then place it in the refrigerator. Refrigerate for at least 4 hours before adding the topping.
Pulse mint Oreo cookies in the blender until it's just crumbs. Set aside.
Add cold heavy whipping cream into the cold mixing bowl. (Use whisk attachment on the electric mixer.) Starting at low speed, start beating and gradually raise speed to high. Slowly pour in sugar. Beat until stiff peaks appear (don't walk away far).
Carefully fold in mint Oreo cookie crumbs. Keep whipped cream in the refrigerator until ready to use.
You may need to warm up hot fudge topping a little bit if it's too solid to pour over the cheesecake.
Pour hot fudge topping over cold cheesecake and spread it all over the top. Let it cool before adding whipped cream topping or it will melt.
Place mint Oreo whipped cream into a piping bag fitted with a frosting tip (I use 1M) and frost the cheesecake as you wish.
You can also decorate the cheesecake with some whole mint Oreo cookies.