Preheat your oven to 325°F (160°C).

Combine graham cracker crumbs, unsweetened cocoa powder, brown sugar, and melted butter. Mix until resembling wet sand, then press into a 9-inch springform pan.

Bake crust for about 10 minutes until firm and lightly browned.

In a large bowl, beat softened cream cheese until smooth, then gradually add granulated sugar and mix until incorporated.

Add eggs one at a time on low speed, mixing just until combined.

Pour in the cooled brewed espresso and optionally coffee liqueur. Mix until smooth.

Pour the filling over the cooled crust and smooth the top. Bake for 55-60 minutes, until the edges are set and center jiggles slightly.

Turn off the oven and crack the door open, allowing cheesecake to cool gradually for 1 hour.

Transfer cheesecake to the refrigerator and chill for at least 4 hours or overnight.

Release the springform pan and garnish with optional chocolate shavings or whole coffee beans before serving.