Method
1. Crush the biscuits until crumb like, by putting them in a plastic freezer bag and crushing them with rolling pin
2. Empty the crushed biscuits into a bowl and mix with the melted butter. Press the mixture into a 23cm springform tin using the back of a soup spoon. then use the back of a spoon. Put the tin into the fridge to firm up the base for half an hour.
3. Put the cream cheese, lemon zest, mascarpone and sugar into a bowl and mix it well with the wooden spoon, then add the lemon juice using a whisk.
4. To whip the cream: Put it in a clean bowl and whisk until it is thick
5. Using a large metal spoon fold the whipped cream into the cheese mixture.
6. Fold in the frozen blueberries
7. Pour the filling over the refrigerated base and spread it evenly. Refrigerate overnight or for a minimum of 6hours