Preheat oven to 150 degrees Celsius. Ensure your bowl is squeaky clean, best to wipe it down with some vinegar
Seperate your eggs whilst they are still cold and allow the egg whites to reach room temperature
Place the room temperature egg whites in the mixing bowl and whisk on low speed. When it just starts forming stiff peaks, start adding a one tablespoon sugar at a time.
Keep whisking, about 3-4 minutes, until the egg whites form stiff peaks. Add the vinegar and cornflour (and vanilla if using) and give it a quick whisk, not more than about 10 seconds. It will look glossy and silky
Draw a circle on some parchment paper and flip it over on a flat baking tray. Transfer the mixture immediately to the lined baking sheet. Use a spatula and form a round ring, make a deep indent in the centre
Reduce the oven temperature to 110 degrees Celsius (fan oven). Cook for one hour and 35 minutes. Do not be tempted to open the oven door. Once baked allow it to cool in the oven preferrably overnight or until it is completely cool.
If you are not serving the Pavlova the same day store the meringue in an airtight container
Whip the fresh cream and spread it in the centre. Top with berries and dust with some icing sugar if desired