Preheat the oven to 350°F. Grease a 9-inch springform pan and wrap the outside of the pan with aluminum foil.
In a food processor, pulse the Oreo cookies until the mixture resembles fine crumbs. Add in melted butter and pulse until well combined. Press mixture into the bottom of the prepared pan in an even layer.
In the bowl of a stand mixer, beat the cream cheese until smooth. Add in sugar and sour cream, and beat until well combined. Add in eggs one at a time, beating well after each addition. Finally, mix in vanilla extract and chopped Oreos.
Pour mixture over the prepared crust. Smooth the top with a spatula. Place the pan into a deep baking dish, and fill the dish with hot water until it reaches halfway up the sides of the springform pan.
Bake for 50 - 55 minutes, or until the edges are set but the center still has a slight jiggle. Turn off the oven and let the cheesecake cool in the oven for an hour before removing.
Meanwhile, make the hot fudge topping by melting the chocolate chips and heavy cream in a saucepan set over low heat. Stir until smooth and well combined, and let cool to room temperature.
Once cooled, pour the hot fudge topping over the cheesecake. Chill the cheesecake in the fridge for at least 4 hours or overnight before serving.