Preheat oven to 350 degrees.

Separate the egg yolks from egg whites. This is easier to do when the eggs are cold. Put the egg yolks into an airtight container and place in refrigerator. Egg whites need to stay out to room temperature. Room temperature egg whites are easier to whip for consistency.

Sift together flour, salt and powdered sugar. Sift together at least 4 times. If using cake flour, sift together once.

Using a KitchenAid/stand mixer (or hand held ~ this will take a while), and using the whisk attachment, whisk the egg whites on medium speed until frothy. 

Add the cream of tartar and vanilla and turn up to high speed. Continue whipping the egg whites until the whites start to form a light foam (mixture will whip up)

After several minutes (3-4), start adding the white granulated sugar in small increments (I slowly shake about 1/4 cup at a time). Let each addition of sugar mix for 30 seconds before adding the next addition. 

Continue to whisk until very stiff peaks form. "Stiff peaks" will be very white and glossy. The peaks should stay firm when you lift the whisk attachment.

Carefully and slowly take 1/3 of the dry ingredients and "fold" them into the egg whites. "Folding" means to take a spatula and gently incorporate the dry ingredients into the egg whites. It's a slow, careful flipping of the ingredients to mix them. Do this 3 times until all the flour/dry ingredients are well mixed in the egg whites. 

Be careful not to deflate the whipped egg whites. You want the cake mix to still be light and fluffy.

Carefully spoon the batter into an ungreased tube pan. Do not use a bundt cake pan, it will overflow! I know, I've done it! ha ha.

Place cake in the center of the oven, on the next to lowest rack. Bake at 350 degrees for 30 - 40 minutes or until a toothpick comes out clean. The top will be medium to dark brown.

When cake is finished baking, take out of oven and immediately flip it upside down on top of a narrow bottle. I usually use a wine bottle or something similar. The neck of the bottle needs to be skinny enough for the pan to slip over it. Let cool completely.

When cake has completely cooled, flip back over onto a serving plate or cake stand. Cake will stay fresh for three days when covered.

Serve a la' natural or with fruit and a big spoon of fresh made whipped cream!