Defrost the raspberries and pass through a sieve. Mix the raspberry puree with 40 g sugar and cover and chill.
Wash lemon hot, dry and finely grate peel. Squeeze the lemon. Whip the sour cream with the whisk of the mixer for about 2 minutes until creamy. Stir in 50 g sugar, lemon juice and zest.
Chill for about 10 minutes. Whip cream until stiff and fold into the sour cream.
Spread a thin layer of lemon sour cream on the bottom of a mould (approx. 18 x 18 cm; rim 5 cm high). Alternately layer butter biscuits (possibly break into pieces to fit the mould), raspberry puree and sour cream in the mould.
Spread the last layer of sour cream on top and spread Lemon Curd in patches. Stir gently into the sour cream. Leave to cool for at least 2 hours and allow to soak.