For the cookie base:

1. Preheat oven to 325°F /170°C.
2. Have ready a 9-inch (24cm) springform cake pan with a removable bottom. 
3. Grind cookies in the food processor until you have fine crumbs.
4. Add the melted butter, and mix until the mixture looks like wet sand. Or add cookie crumbs to the bowl with the melted butter and mix with a spoon.
5. Press this mixture firmly onto the bottom of the pan.
6. Bake for 10 minutes. Let cool on a wire rack while making the filling.
7. Turn the oven down to 300°F/150°C.

For the cream cheese filling:

1. Preheat oven to 300ºF/150°C.
2. In a large bowl, beat cream cheese on low speed until very smooth. You can use an electric mixer or wire whisk. If the cheese is at room temperature, mixing by hand should not be a problem.
3. Gradually add sugar and beat until well incorporated.
4. Add eggs, mixing until incorporated but not beating, and scraping down the sides of the bowl. 
5. Add vanilla, baileys and cream, stirring to incorporate well. Don’t beat. 
6. Pour the batter into the prepared pan and smooth the top.
7. Bake for 20 minutes at 300°F/150°C, turn the oven down to 250ºF/120°C and bake for another 30 minutes. (This can vary depending on your oven). At this point, the cheesecake should jiggle quite a lot in the center. Don't be tempted to bake it longer. 
8. Return the cheesecake to the oven and keep it for 1/2 hour with the door closed. It will keep on baking and firm up with the residual heat.
9. Take the cake out of the oven and spread the topping, leaving a 1/2-inch edge around, being careful not to tear the top.
10. Very carefully, run a small smooth-bladed knife around the edges (top part) to loosen up any bits that might be stuck.
11. Cool to room temperature, wrap the pan in plastic without removing the cheesecake, and refrigerate for 8 to 12 hours. I recommend 1 day for the creamiest consistency.
12. Remove the cheesecake from the cake pan carefully by running a knife around the edges and using a spatula to lift it from the pan. Transfer it to the serving plate and sprinkle chopped white chocolate on top before cutting. 
13. Keep leftovers refrigerated or frozen, covered in plastic wrap or an airtight container. 

For the topping:

1. In a small bowl, mix sour cream and baileys. 
2. You can add a few drops of vanilla extract if you want to. I normally don't.