Preheat the oven to 350°F (175°C).

In a mixing bowl, sift together the cake flour and half of the granulated sugar.

In a separate bowl, beat the egg whites until foamy, then add the cream of tartar and salt.

Continue to beat until soft peaks form, then gradually add the remaining sugar, beating until stiff peaks form.

Gently fold in the flour mixture and vanilla extract until just combined.

Pour the batter into an ungreased tube pan.

Bake for 30-35 minutes, or until the cake is golden and springs back when touched.

Invert the pan and let the cake cool completely before removing from the pan.