Preheat your oven to 325°F (160°C) and grease a 9-inch springform pan.

In a mixing bowl, combine graham cracker crumbs and melted unsalted butter. Press firmly into the bottom of the springform pan, and bake for 10 minutes.

Beat room temperature cream cheese until smooth. Gradually add granulated sugar and Baileys, mixing until fully incorporated.

Blend in the sour cream and add the eggs one at a time, mixing on low just until combined.

Pour the creamy filling over the cooled crust in the springform pan. Bake for 50-60 minutes, until the edges are set but the center remains slightly jiggly.

Let the cheesecake cool in the oven with the door ajar for 1 hour, then transfer to the fridge to chill for at least 4 hours or preferably overnight.

Heat heavy cream until it simmers. Pour over semi-sweet chocolate chunks and stir until smooth to create the ganache.

Pour the ganache over the chilled cheesecake, spreading it evenly. Chill again until set, about 30 minutes.

Remove the sides of the springform pan and garnish with chocolate shavings or whipped cream before serving.