Preheat oven to 400°F (200°C), then reduce to 250°F (120°C).

Beat egg whites with salt for 5-6 minutes until frothy.

Gradually add sugar, vinegar, and vanilla while continuing to beat until stiff peaks form.

Gently fold in cornstarch.

Wet a large oven-safe plate or pie pan with cold water.

Heap the meringue mixture onto the damp surface, forming a circle.

Bake for 1 1/2 hours, ensuring not to overbake.

Turn off the oven and let the pavlova cool completely inside with the door ajar to prevent cracking.