Prepare the Crust:
Preheat the oven to 325°F (165°C).
In a medium bowl, combine graham cracker crumbs, sugar, and melted butter. Stir until everything is evenly coated.
Press the mixture into the bottom of a greased 9-inch springform pan, making sure it's even and compact.
Bake the crust for 10 minutes, then remove from the oven and let it cool while you prepare the filling.
Prepare the Cheesecake Filling:
In a small bowl, dissolve the instant coffee or espresso powder in the hot water. Let it cool slightly.
In a large mixing bowl, beat the softened cream cheese and sugar together until smooth and creamy, about 2-3 minutes.
Add the eggs one at a time, beating well after each addition.
Stir in the vanilla extract, sour cream, and heavy cream, mixing until smooth.
Add the dissolved coffee mixture to the cheesecake filling and mix until fully incorporated.
Pour the cheesecake filling over the cooled crust in the springform pan.
Bake the Cheesecake:
Bake the cheesecake in the preheated oven for 55-70 minutes, or until the edges are set but the center is slightly jiggly (it will firm up as it cools).
Turn off the oven and let the cheesecake cool in the oven for 1 hour with the door slightly ajar.
After cooling, refrigerate the cheesecake for at least 4 hours, or overnight for the best results.
Top the Cheesecake:
Once the cheesecake is chilled, dust the top with cocoa powder using a fine mesh sieve or sifter.
Optionally, sprinkle with additional coffee powder or garnish with chocolate shavings or grated chocolate.
Serve:
Slice the cheesecake, serve, and enjoy!