BROWNIE LAYER

1. Preheat the oven to 180°c. Grease and line a 9” (23cm) square pan with parchment paper, making sure the parchment extends over the sides of the pan to form a ‘sling’. Clip down with binder clips if desired.
2. In a heatproof bowl over a pan of simmering water (make sure the bowl does not touch the water), combine the dark chocolate and butter. Heat, stirring frequently, until the chocolate and butter are melted and the mixture is smooth. Alternatively you can do this step in the microwave - microwave for 30 second increments, stirring well after each until the mixture is smooth and combined.
3. Sift the cocoa powder over top of the chocolate and butter mixture and stir until well combined.
4. In a large bowl, combine the eggs, granulated sugar, and brown sugar. Mix on medium to high speed with an electric handheld mixer for 2-3 minutes until the mixture has lightened and increased in volume. This step can also be done in a stand mixer using the whisk attachment.
5. Add the chocolate mixture and mix to combine. Add the salt and vanilla and mix until incorporated.
6. Add the flour and incorporate by hand until the mixture is smooth and does not have any lumps.
7. Transfer the batter to the prepared pan, and tap the pan on the counter a few times to ensure there are no air bubbles. Leave to sit for a minute or two then bang again to ensure there are no bubbles.

CHEESECAKE LAYER

1. Place all the ingredients for the cheesecake layer in a medium bowl. Combine either with a hand mixer on medium speed, or with a whisk, until the mixture is smooth and lump free.
2. Dollop about 3/4 of the cheesecake mixture on top of the brownie batter, and swirl in using a toothpick or a spoon - I like to scoop down a tiny bit and bring up bits of brownie batter for a nice swirl.
3. Add the rest of the cheesecake mixture and swirl as desired.
4. Bake the cheesecake brownies for 22 to 28 minutes, checking after 20 minutes. You are looking for the edges and top of the brownie to be set, and when a skewer is inserted into the middle, it should come out with a few moist crumbs attached. You are best to lean toward under baking than over baking.
5. Remove the brownies from the oven and place the pan on a wire rack. Leave to cool in the pan then remove using the parchment paper sling. Slice into squares using a sharp knife.
6. Store leftovers in an airtight container at room temperature or in the fridge for up to four days.