If you prefer a sweeter filling, add 100g icing sugar or 10g sweetener to the cheese.
The firmness of the mascarpone may vary from brand to brand. If it is very soft, use 12g gelatine, soaked and dissolved in hot (not boiling) water and add to the cheese. It then requires several hours in the fridge for the filling to set.
The fudge chunks can be mixed in with the cheese filling instead of placed on top.