Preheat your oven to 375°F (190°C) and position the oven rack in the center of the oven.

In a medium mixing bowl, whisk together the powdered sugar and flour until evenly combined. Set aside.

In the bowl of a stand mixer, combine the egg whites, cream of tartar, vanilla extract, almond extract (if using), and salt. Mix on medium speed until frothy.

Increase the mixer speed to high and gradually incorporate the granulated sugar, adding it 1 tablespoon at a time. Wait until each addition dissolves before adding the next, approximately 15 seconds apart. Avoid scraping the sides of the bowl during this process. Continue whipping until the mixture becomes glossy and thick, forming stiff, shiny peaks that hold their shape.

Using a spatula, gently fold the flour and powdered sugar mixture into the whipped egg whites in batches—about ½ cup at a time. Carefully incorporate without deflating the mixture. Fold only until no streaks of dry ingredients remain.

Pour the batter into an ungreased 10-inch tube pan, spreading it evenly. Use a knife or spatula to swirl through the batter and eliminate any large air pockets.

Bake for 35 minutes, or until the surface is golden and springs back lightly when touched. Cracks on the top should appear dry and set.

As soon as the cake is removed from the oven, invert the pan onto a bottle neck or heatproof funnel to cool completely upside down. This helps prevent the cake from collapsing as it cools.

Once cooled, run a knife along the inner edge of the pan to release the cake. Invert onto a serving plate.

Use a serrated knife to carefully slice the cake into portions, using a gentle sawing motion to avoid compressing its delicate structure. Serve plain or topped with fresh strawberries and whipped cream, if desired.