Preheat your oven to 350°F (175°C). Ensure the oven rack is in the lowest position.

• Use a 10-inch (25 cm) tube pan with a removable bottom. Do not grease the pan; Angel Food Cake needs to cling to the sides to rise properly.
• In a bowl, sift together the cake flour and 1/2 cup of granulated sugar. Repeat the sifting process 3-4 times to ensure a light, airy texture.
• In a large mixing bowl, beat the egg whites on medium speed until they become frothy.
• Add the cream of tartar and continue beating the egg whites. The cream of tartar helps stabilize the egg whites and create a fluffy texture.
• Gradually add the remaining 1/2 cup of sugar while continuing to beat the egg whites. Beat until stiff peaks form, and the mixture is glossy. This may take 5-7 minutes.
• Gently fold in the vanilla extract.
• Carefully fold the sifted flour mixture into the egg white mixture. Do this gently to avoid deflating the egg whites. Mix until just combined.
• Spoon the batter into the ungreased tube pan and smooth the top.
• Bake in the preheated oven for 40-45 minutes, or until the top is golden brown and the cake springs back when lightly touched.
• Immediately upon removing the cake from the oven, invert the pan. You can use the pan's legs or the neck of a bottle to keep it elevated. This prevents the cake from collapsing as it cools.
• Allow the cake to cool completely while inverted. This can take 1-2 hours.
• Once cooled, run a knife around the edges to release the cake. Remove it from the pan.
• Slice the Angel Food Cake and serve it with fresh berries and a dollop of whipped cream, if desired.