For the biscuit base
200g petit beurre biscuits
120g unsalted butter, melted
For the filling
150g white chocolate, broken into pieces
200g unsalted butter, softened
125g caster or granulated sugar
1 large egg plus 1 large egg yolk
250g good-quality cream cheese (I recommend Philadelphia)
200g full-fat crème fraîche
Fresh raspberries, to serve (optional)