• Preheat the oven to 375°F. Invert the bottom of a 9-inch springform pan so the cheesecake can slide off onto a serving platter easily. Lock the sides firmly in place. Lightly grease the bottom and sides of the pan. Set aside.
• Cut the cream cheese into 1-inch chunks and set out at room temperature to soften. This will take 30 to 45 minutes depending on the temperature in your kitchen.

To prepare the crust:

• Pour the cookies and powdered sugar into the bowl of a food processor. Process the cookies to fine even crumbs. Add the melted butter and process again until the mixture is evenly moistened and resembles wet sand.
• Transfer the mixture to the prepared pan. Using the bottom of a dry measuring cup press the crumbs into the bottom and slightly up the sides of the pan. Don’t press too hard. Slightly firm is good. Bake until set and fragrant, about 10 minutes. Remove to a wire rack to cool before filling.
• Once cooled wrap the bottom and sides of the pan in a double or triple layer of heavy-duty aluminum foil. Position the springform pan in a large roasting pan and set aside.

To prepare the filling:

• Reduce the oven temperature to 325°F.
• In the bowl of a stand mixer fitted with the paddle attachment beat the cream cheese until smooth and creamy. Scrape down the sides and bottom of the bowl. With the mixer running on medium-low, slowly add the sugar. Beat until the mixture is smooth scraping down the sides and bottom of the bowl as needed.
• With the speed set on medium add the eggs, one at a time, beating just until the yolk disappears before adding the next. Scrape down the sides and bottom of the bowl, beat again to blend. Be careful not to over beat.
• Add the salt, vanilla and sour cream. Blend on low until combined. Scrape down the sides and bottom of the bowl, and mix again for another 5 seconds or until combined. Using a spatula or large spoon fold in three-quarters of the chopped cookies until incorporated.
• Pour the batter into the prepared pan. Top with the remaining chopped Oreos. Fill the outer roasting pan with enough hot tap water to come halfway up the sides of the springform pan.
• Bake at 325°F until the center jiggles slightly, the sides start to puff and the surface appears dry, about 85 to 100 minutes.
• Turn off the oven and prop the oven door open using a pot holder or wooden spoon. Allow the cheesecake to cool in the hot water bath for 1 hour. Transfer the cheesecake to a wire rack and remove the foil. Slide a small thin knife around the inside edge of the pan to loosen the sides of the cheesecake. Leave the cheesecake in the springform pan and cool to room temperature, about 2 hours.
• Cover tightly with plastic wrap and refrigerate overnight, or up to 24 hours.

To serve:

• Remove the sides of the springform pan and carefully slide the cheesecake onto a serving platter. Pipe or dollop the optional whipped cream around the outer edges of the cheesecake. Decorate with whole or crushed Oreo cookies or both.

To prepare the optional whipped cream topping:

• In a cold medium bowl, using an electric mixer, beat the whipping cream on medium speed until soft peaks form. Add the powdered sugar and vanilla and beat on high until firm peaks form. Dollop or pipe the whipped cream on top of the cheesecake in a decorative pattern.