Hands-On: 15 minutes
Total: 1 hr. 50 mins
Yields: 10 to 12 Servings (2 pavlova cakes)
1. Preheat the oven to 275°F. Line a baking sheet with parchment paper, drawing 2 (6-inch) circles on opposite corners, leaving at least a 1-inch clear space for the pavlovas to expand. Flip the parchment paper over so that the pencil lines are baking sheet side down. Set aside.
2. Make the pavlovas at least 2 hours before serving. In a stand mixer fitted with a whisk attachment, add the egg whites to the bowl to warm up a bit. Set aside.
3. In a high-powered blender or food processor, add the sugars, cornstarch, and salt. Pulse on medium-low just until the sugars are fine, not powdered. Set aside.
4. Beat the egg whites at high speed until foamy and soft peaks hold, about 1 minute. Slowly add the sugar mixture to the whipped egg whites, beating until thick and glossy, about 4 minutes. Stop the mixer and scrape down the sides of the bowl. Add the vinegar and vanilla and beat again until stiff peaks hold. The mixture will look like a very thick, glossy buttercream. If it collapses slightly with the folds of a spatula, continue beating until the mixture holds its shape upon a fold.
5. Using a 4 tablespoon-sized spring-release scoop (2-ounce scoop/#16 scoop), scoop out the egg white mixture onto the prepared baking sheet. Shape the meringue cakes by pressing the back of a large spoon into the middle and pulling to spread. The cakes will be thick and rustic in appearance. Bake for 1 hour 15 minutes. When done, the pavlovas will be golden in color and a light tap in the middle will be firm. They should also easily peel off the parchment paper. Remove from the oven and carefully pull away the parchment paper. Place on a cooling rack to cool completely before serving, at least 20 minutes. These can be made a day in advance and stored uncovered at room temperature.
6. Make the fruit salad just before serving. Stir together all the fruit salad ingredients in a bowl, and let sit to give the fruit a chance to release its juices.
7. Prepare the whipped cream just before serving. To assemble, evenly distribute the whipped cream over the cakes