Spray a 9 inch pie plate with non-stick cooking spray. Preheat oven to 300 degrees.

In the bowl of an electric mixer, fitted with a whisk attachment beat the egg whites, cream of tartar and salt until soft peaks form. Gradually add the sugar and continue to beat until the mixture is very stiff and glossy. Rub a little of the mixture between your thumb and forefinger and see if the mixture feels gritty, if so continue to beat until smooth, this will mean the sugar has completely dissolved. Add the vanilla extract and mix in well.

Spread mixture into the prepared pan forming a shell by spreading the mixture up the sides of the pie plate. Bake for 50 minutes. Turn off the oven and leave the meringue crust in the oven for another hour. Remove from oven and allow it to cool completely.

This crust is best used the day it is baked as humidity will soften the crust. It is also preferable to fill the crust just prior to serving.