Pre -heat oven to 100 C fan. Line 2 baking trays with baking paper.
Whip egg whites to soft peaks. Add caster sugar 1 tablespoon at a time to egg whites. This should be thick and glossy.
Sift icing sugar 1/3 at a time over mix and using either a metal spoon or rubber spatula mix icing sugar gently until combined. Do this with the rest icing sugar. The mixture should look smooth and billowy.
You can use a piping bag to pipe out meringue into circles or you can scoop out heaped dessert spoonfuls and using another spoon gently ease onto prepared trays. Cook for 1:1/2 hours, or until meringue sounds crisp when taped underneath.
Whip the cup of thickened cream, add any flavoring you want and sandwich them together and enjoy.