For the Biscuit Base: 

1. Place the digestive biscuits and Kinder Bueno chocolate bars in a sealable plastic bag. Using a rolling pin, crush them into fine crumbs.
2. In a bowl, mix the melted butter with the crumbs until well combined.
3. Spoon the crumb mixture into the base of a 9-inch (23cm) springform cake tin. Press the mixture down firmly and evenly with the back of a spoon to create a flat base.
4. Refrigerate the base for at least 1 hour to set.

For the Cheesecake Filling: 

1. In a microwave-safe bowl, melt the Kinder chocolate in short bursts of about 30 seconds, stirring between each burst until the chocolate is completely melted. Set aside to cool slightly.
2. In a large mixing bowl, combine the cream cheese, powdered sugar, and vanilla extract. Beat until smooth and well combined.
3. Gradually add the melted chocolate to the cream cheese mixture, stirring continuously until fully incorporated.
4. In a separate bowl, pour the heavy cream and whisk until soft peaks form.
5. Gently fold the whipped cream into the cream cheese mixture until evenly combined and smooth.
6. Spoon the cheesecake filling over the chilled biscuit base. Spread the filling evenly with a spatula, ensuring a smooth top.
7. Refrigerate the cheesecake for at least 6 hours, or preferably overnight, to allow it to set completely.

To Serve: 

1. Once the cheesecake has set, carefully release the side of the springform cake tin and transfer the cheesecake to a serving plate.
2. Garnish with whipped cream, extra Kinder Bueno pieces, and a drizzle of melted milk and white chocolate as desired.
3. Slice, serve, and enjoy!