Put the egg whites in a bowl and whip them to soft peaks with an electric mixer at average speed. Continue to beat gradually adding the powdered sugar. A magnificent glossy mass should appear in the end, and the whisk should be coated with stiff peaks. Add starch and vinegar, and stir gently with the egg whites using a flat beater. Add half the vanilla extract and stir again gently. Cover the baking sheet with foil and draw a circle 18-20 cm in diameter with a spoon or fork stem, trying not to damage the foil. Preheat the oven to 140 °C. Carefully spread the egg whites along the foil inside the circle. Make the edges of the meringue slightly higher than the center. Place the baking tray in the center of the oven and bake the meringue for about 1 hour and 15 minutes, or until the color of the egg whites slightly changes. Turn off the oven and leave the door open a bit so that the meringue cools down completely. As the meringue cools, it can crack a little. Take the meringue gently out of the foil and put on a plate. Whip cream with vanilla extract into a fluffy mass. Prepare fruits and berries: wash, dry and cut them, if necessary. Gently lay the whipped cream atop the meringue and decorate with berries and fruits.