In the mixing bowl of an electric mixer, combine the egg whites with cream of tartar and vinegar and beat at high speed until soft peaks form, about 1 minute.
Continue beating, and gradually add the sugar, vanilla and cornstarch. Beat until very stiff, about 2 minutes.
Spoon the meringue mixture into a pastry bag fitted with a star tube.Line a baking sheet with foil or parchment paper.
Dust with confectioners' sugar.
Pipe meringue onto the prepared baking sheet. Use a variety of shapes while piping meringues.
Dust with confectioners' sugar. Place meringues in a 150 degree oven to dry, about 2 to 3 hours.
Store in a sealed container away from humidity. They keep for a week to 10 days.