From the Hummingbird Bakery cookbook (but written out in my own words)
200g dark chocolate
200g unsalted butter
250g icing sugar
110g plain flour
400g cream cheese
150g icing sugar
1/2 teaspoon vanilla extract
Preheat oven to 170C/325F
Melt chocolate in a heatproof bowl over water. Beat butter and sugar together until well combined. Add eggs one at a time, mixing well after each addition. Gradually beat in flour. Mix at medium speed until well combined and smooth. Slowly pour in melted chocolate and mix until well combined. Pour into 33x25cm baking tray, lined with greaseproof paper. Smooth mixture.
Beat together cream cheese, sugar and vanilla until smooth and thick. Add eggs one at a time and continue mixing. Beat until smooth and creamy but do not overbeat or the cream cheese will split. Spoon over the brownie mix and smooth.
Bake for 30-40 mins. The cheesecake should be firm and light golden around the edges. Allow to cool then refrigerate for at least two hours.
If desired, beat together 300ml whipping cream, 100g of icing sugar and 150g raspberries and use as topping.