Begin by melting the chocolate in a heatproof bowl in the microwave. Microwave for 30 seconds at a time, stirring each time until melted. You can also do this using the double boiling method. Set aside to cool slightly.
To a separate bowl, add the cream cheese and mix using an electric hand mixer until creamy. Add the slightly cooled chocolate and mix until well combined.
To a separate medium sized bowl add the cream and whip until you reach soft peaks. Add the mascarpone cheese and vanilla extract and whip to stiff peaks. Transfer the whipped cream to the cheesecake mixture. Use a spatula to fold through until well combined.
Transfer the mixture to the chilled cake tin and spread around evenly using a spoon. Drizzle with raspberry sauce. Use a skewer to swirl around. Chill in the fridge for 2 hours to set.