Using a food processor, blend the raspberries and water until smooth.

In a saucepan over medium heat, combine the sugar and cornflour. Add the raspberry puree and stir constantly until the mixture thickens and comes to a boil.

Allow to boil for 1 minute, then remove from the heat. Allow to cool completely.

Grease the base and sides of a 9" springform pan and set aside.

Stir together the biscuit crumbs and sugar. Add the melted butter and mix until all the crumbs are moist.

Press the mixture into the prepared pan and chill whilst preparing the cheesecake.

Using a handheld or stand mixer, whip the heavy cream until it starts to thicken. Add the icing sugar and vanilla and whip until stiff peeks form.

In a separate bowl, using the mixer again, beat the cream cheese and sugar together until smooth and combined. Add the melted chocolate and mix until combined. Gently fold in the whipped cream.

Divide the cheesecake mixture evenly between two bowls. Add 1/4 cup (about 80g) of the raspberry sauce to one bowl and combine.

Spread the raspberry cheesecake mixture evenly over the cooled crust. Gently top with the white cheesecake mixture and smooth out evenly.

Spread the remaining raspberry sauce on top and chill for at least 6 hours, preferably overnight.

Using a handheld or stand mixer, whip the heavy cream until it starts to thicken. Add the icing sugar and whip until stiff peeks form.

Transfer the whipped cream to a piping bag and pipe swirls on top of the cheesecake. Slice and serve.