Preheat oven to 325 degrees. Spray the sides of the 9-inch springform pan with nonstick baking spray. Wrap the sides of the pan with a strip of parchment paper.
Add the whole Oreos in a food processor and pulse until fine crumbs form.
Pour in the butter and pulse until the butter has coated all of the oreo crumbs.
Pour the crumbs in the bottom of the prepared pan and firmly press them evenly into the bottom of the pan.
Place into the fridge or freezer to firm up while working on the cheesecake batter.
Add the whole Oreos in the food processor and pulse until all of the cookies are turned into fine crumbs.
Add the Oreos to a bowl.
Add the milk to the Oreos and let them sit for 5 to 10 minutes. Whisk the mixture until creamy. Set aside.
In a large mixing bowl, add in the cream cheese. Beat with a hand mixer on medium until smooth.
Add in the sugar and vanilla extract. Beat on medium until combined.
Add in the eggs one at a time and beat just until incorporated. Scrape down the sides and bottom of the bowl before adding the next egg.
Pour about 1 cup of oreo mixture into in with the cream cheese batter. Beat just until incorporated. Adding a small amount will help prevent the batter from forming lumps.
Add the remaining oreo mixture and continue to beat until it's all combined being careful to not overmix the batter.
Just before adding the cheesecake mixture, wrap the outside of the springform pan with 2 layers of heavy-duty tin foil. You can save the foil and put the pan in a slightly larger pan instead.
Pour the cheesecake batter into the prepared pan on top of the crust.
Place the cheesecake into a slightly bigger pan and fill the outer pan with 1 inch of water. If you're not using foil, there this will be the third pan.
Place in the oven and bake for 1 hour 15 minutes – 1 hour 25 minutes until done. To make sure the cheesecake is done, give it a wiggle. If it slightly jiggles in JUST the middle like jello, then it's done. If it jiggles all over, it needs to bake longer. Turn off the heat and crack the oven door slightly. Let it cool in the oven for 1 to 2 hours until it reaches room temperature and then place it in the fridge to chill overnight.
Just before serving, make and add the whipped cream to the cheesecake.
Add the heavy cream and powdered sugar in a large mixing bowl. Using a hand mixer, beat until stiff peaks form.
Place the whipped cream into a piping bag fitted with a 1M tip. Pipe swirls on top of the chilled cheesecake.