Preheat the oven to 225°F (110°C).

Line a baking sheet with parchment paper.

In a clean bowl, beat the egg whites until soft peaks form.

Slowly add the granulated sugar while continuing to whip.

Gently fold in the white vinegar and cornstarch.

Using a spatula, spoon the meringue onto the prepared baking sheet, forming small nests.

Bake in the preheated oven for about 1 hour.

Turn off the oven and let the pavlovas cool inside with the door slightly ajar.