Preheat your oven to a low temperature of 215°F (100°C).
Whip the egg whites in a clean, dry bowl until soft peaks form. Gradually add the granulated sugar, continuing to beat until glossy and stiff peaks form, about 5-7 minutes.
Fold in the white vinegar and cornstarch delicately with a spatula to keep air in the meringue.
Pipe the meringue onto a lined baking sheet, forming small nests with shallow wells in the center.
Bake the meringues for 60-90 minutes, or until the outer edges feel dry and let them cool completely inside the oven.
Whip the heavy cream with powdered sugar and vanilla until soft peaks form.
Top each pavlova nest with whipped cream and scatter fresh berries over the top.
Notes
These pavlovas are customizable with seasonal fruits and can be prepared ahead of time.