Put the cream cheese in a bowl and soften it by microwaving it for 40 seconds. Finely chop the white chocolate, add to a heat-resistant container and microwave for 1 minute. Mix until melted.
Add sugar to the cream cheese in the bowl and mix well with a blender or something similar. (If the cream cheese still seems a little hard, try putting it back in the microwave for a few more seconds).
Add the sour cream, melted white chocolate, heavy cream and egg (in that order) to the bowl and mix well after each addition. Sift the cornstarch into the mixture through a tea strainer and mix well once more.
Line a cake tin with baking paper (for cake tins with a removable bottom, make sure any excess paper on the bottom is flattened down.) Cover the outer bottom of the cake tin with foil to prevent water getting inside.
Pour the mixture into the cake tin and drop lightly onto the counter to remove the air pockets. Place the cake tin on a tray in an oven preheated to 160°C. Pour hot water into the tray and steam the cheesecake for 50 minutes.
We're going to add some decorations so don't worry if there are some small irregularities. Once baked, allow the cheesecake to cool before wrapping and placing in the fridge to chill and harden for 3 hours (though half a day would be best).
Now to make some decorations. Melt the butter in the microwave for 40 seconds before adding the water and sugar and mixing well. Sift in the powdered ingredients and stir again.
Line an oven tray with a piece of baking paper large enough so that the edges are poking over the edges of the tray a little and spread the mixture thinly on top. Add the sliced almonds over that and bake for 10 minutes in an oven pre-heated to 180°C.
Scraping towards you, use the edge of a spoon to create white chocolate shavings. (If you do this step before making the cheesecake you can use the rest of the chocolate in the cheesecake when it becomes too thin to shave without wasting).
When the cheesecake has chilled and hardened, remove from the cake tin.
Once the tuile has completely set, break into jagged pieces and stick to the sides of the cake. Secure everything in place with a ribbon and sprinkle white chocolate shavings over the top to finish.
Note: When adding the egg, if you add 1 egg + 2 egg yolks together you will get an even denser cheesecake. Give it a try!
Story Behind this Recipe
I really wanted to make a dense chocolate cheesecake that didn't collapse or crack after cooking and eventually came to this recipe through much trial and error. Melting the chocolate with hot water takes effort so I tried melting it in the microwave instead this time.
This recipe will result in a firm cake so there was no need to make a base this time. However if you want one, crush 10 crackers or cookies and combine with 40-50 g of melted butter before packing into the base of a cake tin and chilling in the fridge until set. If you don't have black cocoa, you can just use 5 g normal cocoa. Or, if you don't have any cocoa at all, you can make a plain tuile with 10 g cake flour. The tuile will become moist quite quickly, so stick it on the cake right before serving.