Preheat the oven to 325°F (163°C). In a mixing bowl, combine crushed chocolate sandwich cookies with melted unsalted butter, mixing until moistened. Grease and line a springform pan with parchment paper. Press the cookie mixture firmly into an even layer in the bottom of the pan, creating a solid crust. Bake for 10 minutes until set, then remove from the oven and let cool.

In a large bowl, beat softened cream cheese until smooth and creamy. Gradually add granulated sugar and cornstarch, mixing until well combined. Add room temperature eggs one at a time, mixing gently to avoid overmixing. In a separate bowl, whisk heavy cream, sour cream, instant espresso powder, and vanilla extract. Carefully fold this creamy mixture into the cream cheese blend until just combined, ensuring it's smooth.

Pour the filling over the cooled chocolate cookie crust, spreading it evenly. For a water bath, wrap the springform pan in aluminum foil and place it in a larger baking dish filled with hot water. Bake in the preheated oven for 50-55 minutes, until the edges are set and the center has a slight jiggle.

Once baked, turn off the oven and leave the cheesecake inside with the door ajar for about 1 hour. This gradual cooling prevents drastic temperature changes that could cause cracks. Afterward, let the cheesecake cool at room temperature for another 30 minutes before transferring it to the refrigerator. Chill for at least 6 hours or overnight for the best flavor and texture.

Before serving, in a chilled mixing bowl, beat heavy whipping cream with powdered sugar and a touch of instant espresso powder until stiff peaks form. Spread or pipe the whipped cream over the chilled cheesecake for a delightful presentation.

To elevate your Coffee Cheesecake, decorate it with cocoa powder, chocolate shavings, or whole coffee beans. Serve with a hot beverage of your choice.