Mix crushed biscuits with melted butter and press down in a greased 9² spring form tin, chill till filling is made.
For the filling, beat cream cheese, add sugar, lemon rind, eggs, cream and flour. Meanwhile, combine butter, sugar, condensed milk, golden syrup, water in a pan over low heat, keep stirring till sugar is dissolved.
Boil for 4 minutes without stirring then, until deep caramel colour is achieved. Cool. Pour half of cream cheese mixture over the base, put chopped Crunchie chocolate bar and spoon over caramel sauce, then put remaining cream cheese mixture.
Bake at 150 degrees C for one hour or till just set.
Cool. Melt chocolate and cream for the topping, spread over cheesecake and decorate with Crunchie chocolate and serve chilled.