Heat the oven to 120C. Draw 3 x 18cm circles on baking paper, turn paper over and place on two baking trays. Line the base and sides of a 20cm round cake tin with baking paper.
Beat the egg whites until stiff, then add four teaspoons of the measured caster sugar. Continue beating for a further 30 seconds. Sprinkle over the remaining caster sugar and fold in with a spatula, taking care not to over-fold and make the mixture too soft.
Pipe using a piping bag with a plain, 2.5cm nozzle or spread the meringue onto the drawn circles, keeping the meringue within as it will puff out a little during cooking. (Any extra meringue can be made into individual meringues and piped or spooned alongside the meringue circles).
Cook for 1½ -2 hours or until meringue lifts easily off the paper. Turn the oven off and leave to cool in the oven. Once cold, store in an airtight container.
To make the icecream, beat the cream until stiff enough to hold its shape.
Mix together the condensed milk, lemon juice, vanilla and salt. Add to the cream and beat on low until the mixture is thick and creamy, but not overbeaten.
To layer, place a meringue circle in the base of the prepared tin. Place the top of the circle on the base because this will end up being the top of the cake. Pour in half the icecream mixture then top with another meringue circle. Pour in remaining icecream mixture and finish with the last meringue circle. Cover well and place in the freezer overnight.
To serve, remove from the freezer and remove all the paper and place on a serving plate. If you wish, spread a thin layer of whipped cream on top of the icecream cake and finish with cherries. Cut into slices for serving, placing any remaining cake straight back into the freezer.
