Preheat your oven to 325°F (163°C). In a mixing bowl, combine crushed chocolate sandwich cookies with melted unsalted butter until fully combined. Press this mixture firmly into the bottom of a springform pan, creating an even layer. Bake for about 10 minutes, then allow to cool completely.

In a large mixing bowl, beat the softened cream cheese, granulated sugar, and cornstarch until smooth. Gradually add the room temperature eggs, mixing one at a time. In another bowl, whisk together sour cream, heavy cream, instant espresso powder, and vanilla extract before gently folding into the cream cheese mixture.

Pour the filling over the cooled crust. Wrap the bottom of the pan in aluminum foil and place it in a larger baking dish filled with hot water. Bake for 50-55 minutes, until edges are set but center jiggles. Turn off the oven and leave cheesecake inside for an additional hour.

After it has cooled in the oven for an hour, let it sit at room temperature for 30 minutes. Cover with plastic wrap and refrigerate for at least 6 hours, preferably overnight.

Whip the heavy whipping cream in a chilled bowl until it thickens. Gradually sprinkle in powdered sugar and remaining instant espresso, continuing to whip until stiff peaks form.

Release the sides of the springform pan and transfer the cheesecake to a serving platter. Dust the top with cocoa powder and add whipped cream on top. Garnish with optional elements and serve with hot coffee.