Preheat your oven to 350°F (175°C).

Combine the graham cracker crumbs, cocoa powder, brown sugar, and melted unsalted butter in a mixing bowl. Stir until crumbly and well-mixed.

Press the crust mixture firmly into the bottom of a springform pan.

Mix the cream cheese and granulated sugar in another bowl until smooth and creamy, about 2-3 minutes.

Add the vanilla extract and eggs, one at a time, mixing well after each addition.

Stir in the brewed espresso or strong coffee, along with the coffee liqueur if using.

Pour the creamy filling over the set crust and spread it evenly.

Bake for 60 minutes or until the center is set but slightly jiggles.

Cool the cheesecake at room temperature before refrigerating for several hours or overnight.

Serve chilled, topping each slice with chocolate shavings or coffee beans.