Sift the powdered sugar and the cake flour together in a medium sized bowl. add the dash of salt. Set aside.
Preheat your oven to 350°.
In a stand mixer with the whisk attachment or in a large bowl beat the egg whites only until soft peaks form, sprinkle the cream of tartar over and mix again until combined.
Continue mixing on medium while slowly adding the granulated sugar. Do not over beat the egg whites.
Sift 1/3 of the flour mixture over the egg white mixture and lightly fold it in. repeat again with the remaining mixture little by little.
Turn the batter into a large ungreased angel cake tube pan making sure there are no large bubbles in the batter. Lightly smooth the top of the cake batter.
Bake the cake for about 40 minutes in the preheated oven until the top is golden brown.
Take the cake out of the oven and immediately turn the cake upside down to cool. If the cake has risen over the sides you will need to stand it on something like a wine bottle balanced in the center of the pan upside down.
Once the cake has fully cooled loosen the cake from the sides of the pan and frost as desired.