Before starting, preheat the oven to 160ºC/ 325ºF conventional oven. Prepare a 23 cm/9-inch springform tin lined with parchment paper in the bottom.

In a food processor, add the cookies and granulated sugar and blend it all together until a fine sand-like texture. Melt the butter. Add the melted butter to the food processor and blend it together with the blended cookies.

In a 23 cm/ 9-inch spring cake pan add parchment paper to the bottom. Add the cookie crumbs and press the cookie crumbs down with the bottom of a glass, and up against the side of the pan, so it’s well packed together and flattened out.

In a small bowl, mix together the sour cream and cornstarch until smooth. Add it to the cream cheese with the vanilla extract and let it mix on low speed until combined. Then add two eggs at a time and let it mix on low speed until combined. Once all the eggs have mixed in, scrape down the sides of the bowl and give it a final mix to make sure all the ingredients have incorporated.

Boil up water in a kettle. Place the springform pan in a 25 cm/10 inch cake pan. Place the cake pan in another baking pan or roasting pan and fill it with hot water ⅔ up the side of the pan. This method will prevent water from getting into the crust.

Alternatively, add a triple layer of aluminium foil around the cake pan to safely seal it from the water before placing it in a water bath. There might be a possibility of water leaking in, so make sure it's covered well if choosing this method.

Once the time has passed, give the tray a very gentle shake. The cheesecake should still be a small wobble in the middle. Turn off the oven and have the oven door slightly open and let the cheesecake cool down in the oven for 1 hour.

Finally, once at room temperature, place it in the fridge and let it set for at least 6 hours, preferable overnight before eating.

Melt the chocolate and butter in the microwave or over a double boiler. Once melted add the cold heavy cream and with a rubber spatula gently stir it together until smooth.

In a heat safe mixing bowl of your stand mixer or mixing bowl, add the egg whites and sugar. Place the bowl over a saucepan of simmering water, making sure the water does not touch the bowl. With the whisk attachment to your mixer, use it to constantly stir around the mixture until the sugar granules have melted together with the egg whites.

Take it off the heat and place it in your stand mixer or using a hand mixer, and immediately set it at the highest speed. Let it mix for 5-6 minutes until the meringue creates stiff peaks. Then add the vanilla and whisk it in.

Add the meringue on top of the cheesecake and with a kitchen blowtorch give it a torch.