Can Nigella's Chocolate Meringue Truffle Cake from Feast (p294) be frozen?
The filing for the Chocolate Meringue Truffle cake is based on a chocolate and cream mixture, known as a ganache (ganache is used as the filling for truffle, hence the name of the dessert). Ganache itself freezes well so there there is no reason why the filling for this cake should not freeze. The meringue base may however become slightly soft as it will tend to soak up any condensation which forms as the cake thaws. So it may be a little more marshmallowy but we doubt tha anyone will really mind.
To freeze the cake first let it set thoroughly in the fridge (this will take roughly 12 hours). Unspring the cake pan and remove the cake, but leave the base of the springform pan in place as it will provide some extra support to the cake while it is in the freezer. Wrap the cake in a double layer of clingfilm and a layer of foil, label and freeze for up to 3 months. To thaw the cake remove the wrapping and put the cake on a plate (if you have lined the base of the springform pan with baking parchment (parchment paper) then it should be fairly easy to slide the cake onto a serving plate at this point, while it is still frozen). Thaw the cake overnight in the fridge and remove from the fridge and a short time before serving. Dust with cocoa as directed in the recipe.