- Position a rack in the lower third of the oven and preheat oven to 250 degrees. Place one sheet of parchment paper on a sheet pan. Draw a 9-inch circle on the paper using one side of a plate as a guide.
- Place the egg whites and cream of tartar in the bowl of an electric mixer fitted with the whisk attachment. Beat the egg whites on high speed until soft peaks form. With the mixer still on high, gradually add in sugar and cornstarch. Beat until it makes stiff, shiny peaks. Gently fold in the vinegar and vanilla.
- Gently pile the meringue onto the parchment circle, smoothing the sides and top with a spatula.
- Bake 1½ hours. Turn the heat off and let the meringue cool inside the oven for 2 hours.
- Fill the meringue base with whipped cream and your favorite fruit and serve.
- Using a stand mixer fitted with the whisk attachment, whip the cream and vanilla on medium speed until it starts to thicken.
- Add the confectioners sugar and beat until the cream holds soft peaks.