Iced blueberry & lime cheesecake

Method

• step 1

  Line the base and sides of a 20-22cm square cake tin with cling film. Finely grate the zest from the limes and set aside. Squeeze the juice and pour into a pan with the sugar and blueberries. Heat gently to dissolve the sugar, then simmer for 1-2 mins until the blueberries are slightly softened. Remove with a slotted spoon and put in a bowl. Boil the juice for 1-2 mins until it is slightly syrupy, then pour over the blueberries and leave to cool.

• step 2

  Whisk the egg whites until stiff, then gradually whisk in the icing sugar until the meringue is stiff and marshmallow-like in texture. Beat the mascarpone in a large bowl with the lime zest and vanilla. Whip the cream until it just holds its shape, then fold into the mascarpone. Fold in the meringue using the whisk blades.

• step 3

  Break up the amaretti biscuits between your fingers into a bowl to make crumbs. Melt the butter and add to the biscuit crumbs, mixing well.

• step 4

  Spoon the blueberries and their juices into the base of the prepared tin. Spoon the cheesecake mixture evenly over the top, then smooth with the back of a metal spoon to level the mixture. Spoon the amaretti crumbs evenly over the top, pressing down lightly with your hands. Freeze the cheesecake for at least 4 hrs – or overnight is better. Can be frozen for up to two weeks before serving.

• step 5

  To serve, transfer the cheesecake to the fridge for 30 mins. Turn out onto a flat serving plate and peel off the cling film. Serve cut into generous slices.