Preheat oven to 170 degrees celsius and grease and line a 20cm x 30cm pan and line with baking paper.
Place the chocolate into a microwave proof jug and microwave in 20 second bursts until just melted. Stir until the remaining chocolate melts and set aside to cool.
In a mixer with a paddle attachment fitted, beat the butter and sugar for the brownie base until pale and thick.
Add the eggs to the brownie base, one at a time, and beat well after each addition.
Stir in the melted chocolate and then fold through the sifted flour.
Pour ¾ of the brownie base into the prepared pan. Reserve the remaining mixture.
In a seperate mixing bowl, prepare the cheesecake topping. Beat the cream cheese, vanilla extract, sugar and eggs until smooth.
Spread the cheesecake topping over the brownie base. Dollop the reserved brownie mixture on top of the cheesecake base and swirl through with a fork.
Sprinkle with the raspberries, pushing the raspberries into the cheesecake topping.