Spread a layer of the meringue on the base of the third loaf tin (not too thick). Cut the sponge in half horizontally and spread the apricot preserve over both of the cut ends. Lay one piece of the sponge, jam-side up, over the meringue then unmould the ice-cream, trim and lay on top. Now place the second piece of sponge, jam-side down, over the ice-cream. Use the remaining meringue to cover the top of the alaska so that it completely seals the cake, like an igloo! Place the alaska in the freezer until solid.