Heat your oven to 180°C (160°C fan) and line a 22-23cm square tin.
Melt the chocolates with the butter in a microwave or in a bain-marie.
Add the sugar, the eggs, and the cocoa powder.
Bake for 20 minutes. Cool down and refrigerate for 15 - 20 minutes.
To make the cheesecake, first place the vanilla pod in warm water to soften it, then split it and scrape out the seeds.
Beat the cheese and sugar in a bowl with an electric mixer until smooth.
Add the eggs, one at a time, beating well after each addition, then beat in the vanilla seeds.
Pour the cheesecake filling on top of the brownie and cook for an additional 20 - 30 minutes until just set.
Leave to cool.
To decorate: melt the remaining chocolate and drizzle over the cake.
