Preheat the oven to 375 degrees F (190 degrees C). Clean and fully dry a 10-inch tube pan. I use a bundt pan and it works great.
Sift together flour, and 3/4 cup sugar, set aside
Whip egg whites, along with vanilla, cream of tartar, and salt, in a large bowl to medium stiff peaks. Gradually add remaining 3/4 cup sugar while continuing to whip to stiff peaks. When the egg white mixture has reached its maximum volume, fold in the sifted ingredients gradually, 1/3 at a time. Do not overmix. Put the batter into the tube pan.
Bake in the preheated oven until the cake springs back when touched, 40 to 45 minutes.
Balance the tube pan upside down on the top of a bottle to prevent decompression while cooling. When cool, run a knife around the edge of the pan and invert onto a plate.
Notes
If you don't have cake flour you can make it by replacing TBSP of the all purpose flour with 2 TBSP of corn starch!