Sift together the cake flour and 1/2 cup sugar. Set aside.
In a stand mixer with a metal bowl and whisk attachment, combine egg whites, salt, cream of tartar, vanilla, and almond extract. Whip until soft peaks start to form. Add the rest of the sugar in 4 separate additions, blending until each addition is absorbed. Do not scrape the sides of the bowl.
Add the flour mixture in 4 seperate additions, FOLDING it into the batter with a metal serving spoon. Using the same metal spoon, spoon the batter into an ungreased metal angel food bundt pan. Gently smooth out the top and run a knife through the middle of the batter to give it room to expand.
Bake for 35 minutes or until a wooden toothpick inserted in the middle comes out clean. Invert the cake pan upside down onto a bottle and cool for at least an hour upside down.
Once the cake is cool, prepare the frosting in a mixing bowl with a hand mixer. Using an offset spatula, frost the cake. Top with summer berries as desired.