Preheat the oven to 250°F (120°C)
Line a baking sheet with parchment paper
Beat egg whites until soft peaks form
Gradually add sugar while beating until stiff, glossy peaks form
Add cornstarch, vinegar, and vanilla extract
Gently fold until just combined
Spoon the meringue onto the parchment paper
Shape into a round with a slight well in the center
Bake for 1 hour
Turn off the oven and let the pavlova cool completely inside
Whip heavy cream until soft peaks form
Spread the whipped cream over the cooled pavlova
Top with fresh fruit before serving