Preheat oven to 170°C and line three cake tins (13cm, 18cm, and 23cm) with parchment.
Melt butter and dark chocolate, stir in shortbread, press into tins, and chill.
Melt white chocolate gently over a pan of hot water until smooth.
Whisk cream cheese, eggs, soured cream, and vanilla until smooth, then stir in melted chocolate.
Layer half the mixture, raspberries, and remaining mixture into the tins.
Bake the 13cm for 30-35 mins, 18cm for 35-40 mins, and 23cm for 40-45 mins until set.
Pulse 50g raspberries with icing sugar, sieve into a purée, and discard seeds.
Stack cheesecakes using cake boards and dowels to support the layers.
Pipe double cream rosettes around edges, top with raspberries, and pour coulis on top tier.
Create white chocolate curls and arrange them over the top tier.