Preheat the convection oven to 110°C / 230°F and line one baking sheet with parchment paper.

Draw a 20 cm circle on the parchment paper, then turn the paper ink-side down on the baking sheet.

Whisk 150 g egg whites in a clean mixing bowl until foamy, then continue whisking until soft peaks form.

Add 300 g superfine sugar one tablespoon at a time, then whisk well after every addition until the crystals dissolve.

Whisk in 15 ml white vinegar and 5 ml vanilla extract at low speed.

Add 25 g cornstarch and the optional cream of tartar, then whisk until the meringue is stiff and glossy.

Transfer the meringue to the piping bag fitted with a plain round piping tip, then pipe a ring inside the drawn circle.

Pipe or spread remaining meringue across the centre, then shape a slightly raised edge to hold the filling.

Bake the pavlova for 90 min, then turn off the oven and leave it inside for 30 min with the door slightly open.

Cool the pavlova completely, then transfer it carefully to a serving plate.

Whip 400 ml heavy cream until soft peaks form, then spread it over the cooled meringue.

Top with 125 g raspberries and 100 g strawberries, then dust lightly with edible gold dust before serving.