Preheat oven: preheat the oven to 180°C / 350-375°F / Gas Mark 4-5.
Slice tin: line a square 23cm (or 9 inch) slice tin with 2 sheets of overlapping baking paper and 2 inch over hang on either side. Note 7
Caramel cheesecake layer: add the cream cheese, eggs, vanilla and sugar to a medium sized mixing bowl. Then set aside.
Brownie layer: add the sugar and salt to a large mixing bowl. Then add the dark chocolate chips and butter to a heatproof jug. Microwave (high heat) the chocolate and butter in 30 second increments (for 1 ½ minutes) and then remove and stir gently. Pour this into the sugar and salt then stir to combine. Add the eggs and vanilla then stir to combine. Next add the flour and cocoa powder and gently stir to fold in.
Oven bake: use a rubber spatula to spread the wet brownie batter over the base of the prepared slice tin. Then place this uncovered into the oven (middle shelf) and let it bake for 20-25 minutes.
Caramel cheesecake layer: return to the bowl with the cheesecake ingredients and use electric beaters to beat till smooth and lump free.
Combine: use oven mitts to remove the slice tin from the oven and set it on a heatproof surface. Pour the cheesecake layer over the top and use the spatula to spread the cheesecake mixture across the top in one smooth layer.
Caramel: rinse the beaters, dry them and then in a separate bowl use them to whisk the caramel until it is a thick, smooth sauce. Then use a teaspoon to dollop this onto the cheesecake layer. Once done use a chopstick or skewer to swirl so that the layers are mixed together.
Oven bake: using the oven mitts gently tap the slice tin on the bench top to remove air bubbles then place the brownies back into the oven. Let them cook for a further 20-25 minutes. Once cooked they will puff up around the center and pull away from the edges of the slice tin. A skewer inserted will have only a few crumbs no wet smear on it.
Cool: let the cooked brownies cool in the tin for at least 1 hour (can be in the fridge). Once they have use the baking paper overhang to lift them up and out of the pan. Discard the paper and then slice the brownies into 16 evenly sized portions.