3 lemons, zest and juice (about 80ml/2¾fl oz)
75²µ/2¾´Ç³ú lemon curd
140g/5oz icing sugar, sifted
275g/9¾oz gingernut biscuits
100²µ/3½´Ç³ú butter, melted, plus extra for greasing
625g/1lb 6oz full-fat cream cheese
150ml/5fl oz double cream