Preheat the oven to 180C (350F). Line a baking tin with baking paper and set aside. 

Break the chocolate apart and cut up the butter, placing in a microwave safe bowl. Melt this mixture in the microwave until soft, using 30 second intervals and stirring in between until the chocolate is just melted. 

Take the bowl out of the microwave and stir in the sugar, eggs and vanilla extract until combine. Add the flour and stir until it is incorporated, then pour this evenly into the baking tin, using a spatula to smooth down the top. 

In another bowl, whisk together the cream cheese, caster sugar, egg yolk and vanilla extract, until the mixture has no lumps. 

Seperate the cheesecake batter into two bowls, and add the two drops of red food dye to one bowl. Stir to combine, adding more food dye until you get the desired colour. 

Use a spoon to drop plain and pink cheesecake batter over the brownie batter until you have all the cheesecake batter on the brownie. Use a spatula to spread it evenly on top of the brownie batter, then get a butter knife and swirl the brownie mixture through parts of the top to create a pattern. 

sprinkle the raspberries over the top of the batter, submerging some of them with the knife. Touch up the pattern as needed. 

Cook the brownies for 30-35 minutes or until golden on the top. Although it may be gooey, it will firm up as it cools. Wait until the brownies are completely cool to cut into even pieces.