Preheat the oven to 225°F. Line a large sheet tray with parchment paper, set aside.
In the body of a stand mixer add the egg whites and the salt. Mix on medium speed until soft peaks form about 5 minutes. Add the powdered sugar one tablespoon at a time to the bowl, scraping down the sides as needed. Turn the speed onto medium-high and whip until stiff peaks form, the egg white will become glossy and bright white, about 5-8 minutes. Fold in the cornstarch, vinegar, and vanilla until fully mixed.
Place six even dollops of the meringue onto the sheet tray about 3 inches apart. Slightly flatten them out until they are an inch and a half high, make a little divet in the center, this is where your toppings will sit.
Place in the oven and bake for 1 hour and 15 minutes.
Without opening the oven, turn off the heat and let cool down completely. This will take about 6 hours. Use immediately or store in an airtight container until ready to serve.
Top with whipped cream and strawberries just before serving.
Notes: Do not make on a humid or rainy day, the meringue will not dry properly.