1. Remove the cream cheese, eggs (and yolks) and sour cream from the refrigerator and allow it to come to room temperature.

For the Crust

1. Preheat the oven to 325°F. Line a 9-inch springform pan with parchment paper in the bottom.
2. Grind the cookies into a fine crumb using a food processor or blender.
3. In a small bowl, melt the butter in the microwave for 30 to 45 seconds. Pour the melted butter over the cookie crumbs and stir until the crumbs are well coated.
4. Pour the crumbs into your springform pan and press firmly into the bottom and up on the sides to create a thick crust. Then wrap the bottom of the pan in tin foil and then place a slow cooker liner over top of the foil and tie a knot in the side of the bag to secure around the pan. Set aside.

For the Filling

1. In a microwave-safe bowl, microwave the chocolate at 50% power in 30-second increments, stirring each time until the chocolate is melted. Stir until completely smooth.
2. In a large mixing bowl, beat the cream cheese for 2 minutes until free of lumps then add the sugar and beat on low speed until completely smooth, scraping down the bowl occasionally.
3. Next add the cocoa powder, sour cream and vanilla extract and mix on low speed until well combined.
4. Scrape down the bowl and add the melted chocolate and Baileys, beating until combined.
5. Add the eggs one at a time, ensure it’s well mixed before adding more. Scrape down the bowl occasionally. Pour the cheesecake batter into the prepared crust. Gently tap the pan on the counter to remove any air bubbles on the surface or use a toothpick.
6. Place the springform pan inside another larger pan. Fill the outside pan with approximately 2-3 cups of warm water so it about halfway up the sides of the springform pan.
7. Bake at 325°F for approximately 55-60 minutes. The center should be set, but still slightly jiggly. Turn off the oven and leave the door cracked open for 1 hour.
8. Remove the cheesecake from the oven and water bath and cool for at least 1 hour on the countertop, then cover and move to the refrigerator. Refrigerate for 4-6 hours until the cheesecake has set.

For the Topping

1. Prepare a batch of whipped cream by placing your bowl in the freezer for 5-10 minutes. Pour the heavy whipping cream into the chilled bowl and use an electric mixer to beat the heavy cream at medium-high speed until soft peaks form. Add the Baileys and the powdered sugar and continue beating at high speed until stiff peaks form. Pipe the boarder on the outside edge of the cheesecake.