Preheat your oven to 300°F.

Using a stand mixer or electric hand beaters, beat egg whites until stiff peaks form.

Gradually add in the granulated sugar, one tablespoon at a time, while beating continuously until the mixture is thick and glossy.

Add in the vinegar, vanilla extract, and cornstarch, and gently fold until everything is well combined.

Line a baking sheet with parchment paper and scoop the mixture onto the sheet, forming a large circle or several smaller circles. Using a spatula, make a shallow depression in the center of the pavlova to hold the topping.

Bake the pavlova for approximately 1 hour or until it has a crisp exterior and is soft and marshmallowy inside.

Leave the pavlova in the oven to cool for several hours, or overnight, with the oven door slightly open.

Once cooled, whip the heavy whipping cream along with the powdered sugar until soft peaks form.

Spread the whipped cream on top of the pavlova and decorate with fresh fruit of your choice.