Make the cheesecake mixture: In a medium sized bowl, whisk together the cream cheese, sugar, baileys, ground almonds, vanilla extract and egg yolk until smooth. Leave to one side
Make the brownie mixture: Preheat the oven to 165 Fan and line a 23 x 33 centimeter deep baking tray with baking paper
In a bowl, mix together the melted dark chocolate, melted butter, baileys and vanilla extract
Into a large bowl, add the dark brown sugar, ground almonds, cocoa powder and baking powder. Mix well.
Add the wet ingredients to the dry and whisk together till thoroughly combined. Add one egg at a time, mixing each addition well until silky smooth. To finish, add in the chocolate chips and stir through
Pour ¾ of the brownie mixture into a deep lined baking tray. Leave the remaining ¼ to one side. On top of the brownie mixture, add the cheesecake mixture and use a palette knife to help spread evenly. Dollop the remaining ¼ brownie mixture on top, before using a knife to marble together the two batters.
Place in the oven and bake for 35 minutes. When cooked, leave to cool in tray for 10 minutes before transferring to a cooling rack. Leave to set for 1 hour before slicing and serving