For the blueberry pavlova, beat egg whites with vinegar and salt until stiff. Mix 150 g sugar, vanilla sugar and the cornstarch and add to the beaten egg whites.
Continue beating until the whisk pulls stiff peaks. Place baking paper on a baking sheet and spoon 8 meringue mounds onto it.
Spoon the blobs evenly in a circle, pressing a well into each hood. Bake for 10 minutes, reduce the heat to 90 °C and continue baking for 1 hour.
Turn off the oven and let the hoods cool in the oven for 1 hour more, leaving the door ajar.
Whip the whipped cream with the remaining sugar until stiff. Crush 75 g of blueberries, fold them and the whole blueberries into the whipped cream and then pour into the cavities of the hoods.