To make the meringue layers, preheat oven to 100°C. Cut 2 pieces of non-stick baking paper large enough to line 2 baking trays (pizza trays are perfect for this).
Use a pencil to draw a circle (23cm in diameter) onto each piece. Place the baking paper onto the trays with the pencilled side down.
Whisk the egg whites using electric beaters until soft peaks form. Gradually add the sugar, a spoonful at a time, whisking well after each addition.
Add the vanilla with the last addition of sugar and whisk until thick and glossy and soft peaks form when the beaters are lifted. Spread the meringue mixture into discs on the lined baking trays using the circles as a guide.
Bake in a preheated oven for 2 1/2-3 hours or until crisp and dry. (It is important the meringue is cooked at this low temperature for a long time to achieve the crisp texture without browning.)
Remove from the oven and cool on the trays. Store in an airtight container for up to 2 days.
To assemble, whisk the cream until firm peaks just form. Place one of the meringue discs on a serving plate or cake stand and spread with half the cream. Sprinkle with half the chopped chocolate and cover with the remaining meringue disc.
Spread with the remaining cream, top with strawberries and blueberries and sprinkle with the remaining chocolate. Serve within 3 hours of assembling.
