In a food processor or a mini chopper, blend sugar until it becomes fine but not powdered.
In a bowl, sift together cake flour, salt and 1/2 of the fine sugar.
Combine egg whites, warm water, and cream of tartar in the stand mixer bowl. Whisk together in a low speed for 30 seconds. Change the speed to medium high and sprinkle 1/2 of the fine sugar while mixing continuously until medium peaks.
Take the bowl out of the stand mixer. Add the vanilla extract, lemon zest and lemon juice. Fold with a spatula.
Slowly sprinkle the cake flour mixture and fold in gently with a spatula until cake flour mixture is gone.
Spoon the mixtures into an ungreased tube pan. Smooth the top so it is even.
Place the tube pan in a cold oven. Turn the oven on to 325 degrees F and bake for 1 hour.
Invert cake and cool it in the pan. Once it is completely cool, remove the removable bottom and scrapes the sides and bottom of the pan.
LEMON GLAZE
In a medium bowl, whisk together the powdered sugar, lemon juice and lemon zest. Add milk if its not runny enough or add powdered sugar if its too runny.
Pour the glaze all over the cake.
Invert cake and cool it in the pan. Once it is completely cool, remove the removable bottom and scrapes the sides and bottom of the pan.