To adjust for high altitude drop the oven temperature to 315˚ and you might need to bake it a bit longer.
Ingredients
1½ cups egg whites (10-12 large), room temperature
1½ teaspoons cream of tarter
1 teaspoon vanilla extract
1 cup granulated sugar
1½ cups sifted powdered sugar
1 cup sifted cake flour or sifted all-purpose flour
Preparation Instructions
Preheat oven to 350˚. Set out your tube pan but do not grease it as this makes it harder for the cake to rise.
In the bowl of an electric mixer, fitted with the whisk attachment whisk the egg whites, cream of tarter and vanilla until stiff peaks form. Stiff peaks are when you dip the whisk in the whites and pull it out and the whites stand stiffly up without falling over.
Once you have stiff peaks, put the mixer on medium speed and gradually add the granulated sugar.
In another large mixing bowl, combine the flour and powdered sugar.
Then use a spatula to fold ¼ of the flour mixture into the egg whites, repeat with remaining egg whites ¼ at a time and be very gentle so you don't deflate the whites.
Pour the mixture into the tube pan and then run your spatula around in the batter to get rid of any air bubbles.
Bake for about 40-45 minutes or until the top is nice and golden and springs back when gently pushed.
Immediately invert the cake to cool. Some tube pans have little feet so you can do this directly on the counter but some don't. If yours does not, an old wine bottle works wonderfully.
Once completely cooled, loosen the edges of the cake and remove it gently.
Recipe by Foods of Our Lives at https://www.foodsofourlives.com/2013/06/angel-food-cake/