Roughly crush the biscuits by putting them in a plastic food bag and using a rolling pin. Put the biscuits into a bowl and mix in the melted butter. Push the mixture down into a 23cm cheesecake tin and use the back of a spoon to spread it evenly. Put the tin into the fridge to set. This takes about 30 minutes. Put the cream cheese, orange zest, mascarpone, sugar and milk into a bowl and mix well.
Put the cream in a clean bowl and mix until it reaches a thick consistency. Add to the orange mixture and mix thoroughly.
Take the cheesecake tin out of the fridge, pour in the filling over the biscuit base and spread evenly. Decorate with the orange segments and some chocolate curls. Place in the fridge to chill for at least 4 hours although overnight is preferable.