Step 1: Preheat your oven to 350°F (175°C). Lightly grease a 9-inch springform pan. Crush your Oreo cookies finely. You should have about 2 cups of crumbs.
Step 2: In a medium bowl, combine the cookie crumbs with 1/2 cup (113g) of melted unsalted butter and 2 tablespoons of granulated sugar. Mix until the crumbs are evenly moistened.
Step 3: Press the crumb mixture firmly into the bottom of the prepared springform pan. Bake for 8-10 minutes, then remove from the oven and let cool slightly. Reduce oven temperature to 325°F (160°C).
Step 4: In a large mixing bowl, using an electric mixer, beat 24 ounces (680g) of softened full-fat cream cheese on medium speed until smooth and creamy, about 2-3 minutes. Scrape down the sides of the bowl as needed.
Step 5: Gradually add 1 1/2 cups (300g) of granulated sugar to the cream cheese, beating until well combined and fluffy, about 2 minutes.
Step 6: Beat in 1/2 teaspoon of pure vanilla extract and 1 teaspoon of pure peppermint extract.
Step 7: Add 4 large eggs, one at a time, beating on low speed just until each egg is incorporated. Scrape down the bowl after each addition.
Step 8: Stir in 1/2 cup (120g) of sour cream until just combined.
Step 9: Prepare a water bath. Wrap the bottom and sides of your springform pan tightly with several layers of heavy-duty aluminum foil. Place the foil-wrapped pan into a larger roasting pan.
Step 10: Pour the cheesecake filling over the cooled crust in the springform pan. Place the roasting pan into the preheated 325°F (160°C) oven. Carefully pour hot water into the roasting pan, around the springform pan, until it comes about halfway up the sides of the springform pan.
Step 11: Bake for 60-75 minutes, or until the edges are set but the center still has a slight wobble when gently shaken.
Step 12: Turn off the oven, crack the oven door slightly, and let the cheesecake cool in the water bath in the oven for 1 hour. Remove from the water bath and foil.
Step 13: Let the cheesecake cool completely on a wire rack at room temperature for another 1-2 hours.
Step 14: Once cooled, cover the cheesecake loosely with plastic wrap and refrigerate for at least 6-8 hours, or preferably overnight.
Step 15: Once the cheesecake is thoroughly chilled, prepare your topping. In a microwave-safe bowl, combine 1 cup of chocolate chips with 1/2 cup of heavy cream. Microwave in 30-second intervals, stirring in between, until smooth and glossy.
Step 16: Pour the chocolate ganache over the top of the chilled cheesecake, spreading it evenly. Let it set for about 10-15 minutes at room temperature, or briefly in the fridge.
Step 17: Generously sprinkle 1 cup of coarsely chopped peppermint bark over the top of the chocolate ganache. Optionally, add extra crushed candy canes for garnish. Serve chilled.