Preheat oven to 170 degrees C and line a 20cm square baking tin with nonstick paper
Add all of the ingredients apart from the chocolate to a food processor and process until smooth (3-4 minutes). The mixture will be thick and sticky.
Fold in your chopped chocolate
Spread batter evenly into your tin and if you choose, sprinkle the top with your cacao nibs. These give a nice crunch once baked and add an extra texture.
Bake in the centre of the oven for 20 minutes, or til a skewer comes out clean.
Cool on a wire rack. Cut into 16 squares once cool.