1. Preheat the oven to 225°F (110°C). Lightly grease 2 large cookie sheets and line with baking parchment. Place the egg whites into a large, spotlessly clean mixing bowl and whisk them until they form stiff peaks. Add the sugar a tablespoon at a time, whisking well after each addition, until the mixture is smooth, thick, and glossy.
2. Place heaped teaspoons of the mixture, spaced a little apart, onto the prepared cookie sheets, until you have 30 meringues. Flatten slightly.
3. Bake in a preheated oven for 1 hour, or until they peel off the baking parchment. Leave to cool.
4. Whisk the vanilla sugar into the cream until thick. Spread some cream on the flat side of a meringue, put some strawberries on top, spread some cream on another meringue, and sandwich together.