Creating your Guinness Cheesecake is a simple process if you follow these detailed steps:

1. Preheat the Oven: Begin by preheating your oven to 325°F (160°C). Prepare a 9-inch springform pan by greasing it lightly.

2. Make the Crust: In a medium bowl, combine the graham cracker crumbs, cocoa powder, granulated sugar, and melted butter. Mix until well combined, then press the mixture firmly into the bottom of the prepared springform pan.

3. Bake the Crust: Place the crust in the preheated oven and bake for 10 minutes. Remove and allow it to cool while preparing the filling.

4. Prepare the Filling: In a large mixing bowl, beat together the softened cream cheese and granulated sugar using an electric mixer until smooth.

5. Add the Eggs: Add the vanilla extract and eggs, one at a time, to the cream cheese mixture, beating until each is fully incorporated.

6. Incorporate Guinness: Gradually add the Guinness stout and sour cream, mixing until the filling is smooth and creamy.

7. Pour the Filling: Carefully pour the cheesecake filling over the cooled crust in the springform pan.

8. Bake the Cheesecake: Bake in the preheated oven for 50-60 minutes, or until the edges are set and the center has a slight jiggle.

9. Cool the Cheesecake: Turn off the oven and crack the door open, allowing the cheesecake to cool gradually for about 1 hour. Then, transfer it to the refrigerator to chill for at least 2 hours, or overnight for best results.

10. Prepare the Topping: To make the ganache, heat the heavy cream in a small saucepan until just simmering. Pour the hot cream over the chocolate chips in a bowl and let sit for 5 minutes. Stir until smooth.

11. Top the Cheesecake: Once the cheesecake is completely cool, pour the ganache over the top, smoothing it out as needed. Refrigerate for an additional 30 minutes to set the ganache.