Preheat oven to 350 degrees.  Line cupcake pans with paper liners.

Place egg whites in a large mixing bowl and beat at high speed until egg whites are frothy, approximately 1 minute.

Add cream of tartar, salt and vanilla to egg whites.  Mix at high speed until egg whites are almost stiff, approximately 4 minutes.

Add 1 cup of sugar gradually while mixing on low speed.  Scrape bowl.

Mix flour and remaining 1/2 cup sugar together and spoon 1/4 of mixture over egg whites, folding gently between each addition.

Pour batter into cupcake liners until they are 2/3 full.  Bake for 20 to 25 minutes or until tops are golden brown and cracks are very dry.

Cool cupcakes completely before removing from pan.