Crush the biscuits in a plastic bag with a rolling pin, until they resemble breadcrumbs.
Stir the melted butter thoroughly into the biscuits. Press into the base of a greased 20cm springform tin (or loose bottom cake tin) and chill in the fridge for 10 mins until the base is slightly hardened.
Using an electric whisk, beat together the cream cheese, sugar, lemon zest and juice, until smooth.
Melt the white chocolate in a heatproof bowl set over a saucepan of barely simmering water. Once melted, slowly pour the chocolate into the beaten ingredients, whisking as you do so. Fold in the whipped cream.
To assemble the cheesecake, scatter half the raspberries over the biscuit base and pour half the cream filling over. Repeat with the remaining raspberries and filling and level the top with the back of a spoon.
Leave to chill in the fridge for 4 hours or overnight.