Preheat the oven to 325°F (160°C).
In a mixing bowl, combine the graham cracker crumbs, melted butter, and sugar for the crust. Mix until well combined.
Press the crust mixture firmly into the bottom of a 9-inch springform pan to form an even layer.
In a large mixing bowl, beat the softened cream cheese and granulated sugar together until smooth and creamy using an electric mixer.
Add the sour cream, Baileys Irish Cream, and vanilla extract to the cream cheese mixture. Mix until well combined.
Add the eggs one at a time, mixing well after each addition. Do not overmix.
Pour the cheesecake filling over the crust in the springform pan. Smooth the top with a rubber spatula.
Bake in the preheated oven for about 60 minutes or until the center is set but still slightly jiggly.
Turn off the oven and leave the cheesecake inside for 1 hour to cool slowly.
Remove the cheesecake from the oven and allow it to cool completely at room temperature.
Once cooled, refrigerate the cheesecake for at least 4 hours or overnight for best results.
Before serving, if desired, top with whipped cream and garnish with chocolate shavings or cocoa powder.