Place the biscuits in the food processor and blitz to a fine crumble, or place them in the zip lock bag and crush using the rolling pin. Melt the butter in a saucepan. Pour the butter over the crushed biscuits while the food processor is running and mix well.
Place the cake rings on a baking tray lined with baking paper. Use a baking tray that will fit into the fridge. Tip the crumb mixture into the cake rings and firmly smooth the top. Put in the fridge until needed.
Beat the cream with a mixer until stiff. Squeeze the lime. In another bowl, combine the cream cheese with the icing sugar and lime juice. Mix well. Fold the whipped cream through this mixture as lightly as possible. Spoon the cream cheese mixture into the chilled cake rings. Leave the cake in the fridge to firm for at least 2 hour.
To serve, remove the rings and garnish the top with the raspberries and blueberries.
No waste tip: Scrub the lime and zest the peel. Add the zest to the cream cheese. Even more zingy flavour!
Tip: Instead of using individual cake rings, you can also use a springform of 22 or 24 cm Æ, to make one large cheesecake.
