Separate the egg whites and leave sit at room temperature for at least 1 hour.
Preheat the oven to 350 degrees Fahrenheit.
Sift together the flour and 3/4 cup of sugar. Sift 4 times and set aside.
Using a stand mixer with the whisk attachment, add the egg whites and cream of tartar to the bowl.
Beat on medium speed until the egg whites hold a soft peak. Do not overbeat.
Stir in the salt and vanilla extract.
Turn the mixer to medium-high speed and gradually add in the remaining 1 cup of sugar. Do this quickly, but gradually. Beat until stiff peaks form. The batter will look glossy. Scrap the side of the bowl down as needed.
Remove the bowl from the mixer and using a rubber spatula gently fold in the sifted flour and sugar mixture. Blend until well combined, but do not over-mix.
Gently spoon the batter into a large tube cake pan. Do NOT grease the cake pan.
Cut a knife through the batter to remove any air pockets.
Bake at 350º F for about 35-40 minutes. The top should be golden brown and have dry-looking cracks that spring back when gently pressed.
Remove the cake from the oven and immediately turn the pan upside down to cool. I place the center of the tube on a glass to elevator it.
Once the cake is cooled, run a knife around the inside and bottom of the pan to release the cake from the pan.
Decorate with your favorite frosting or glaze, or serve plain with fresh berries and whipped cream.