Grease a 23cm loose-bottomed cake tin and line with parchment paper.
Preheat the oven to 160°C.
Crush the biscuits and mix with melted butter and demerara sugar.
Press the mixture firmly into the base of the tin and leave to set.
Beat the butter, sugar, cheese, flour, lemon juice, rind, and egg yolks until smooth.
Fold the lightly whipped cream into the cheese mixture.
Whisk egg whites until stiff and fold them into the mixture.
Pour the mixture over the biscuit base and level the surface.
Bake for 60 to 75 minutes until set.
Turn off the oven and leave the cake inside for one hour to cool.
Loosen the edges with a knife and remove the cake from the tin.
Place the cheesecake on a serving plate and remove side paper.
Top with whipped cream and mixed fruits, then dust with icing sugar.