Preheat your oven to 350°F (175°C). Ensure your oven rack is in the center and gather your equipment.

In a large mixing bowl, whip room-temperature egg whites on medium speed until soft peaks form, about 2-3 minutes. Gradually add sugar, then beat until stiff peaks form.

Sift cake flour over the whipped egg whites and gently fold in using a spatula to maintain the airiness.

Fold in the raspberries carefully, incorporating them without breaking them apart.

Pour the batter into an ungreased angel food cake pan, smoothing the top with a spatula.

Bake for 30-35 minutes until the cake springs back when touched. It should be golden brown.

Invert the pan onto a wire rack immediately to cool upside-down, maintaining the cake's light structure.

Once cooled, run a knife around the edges of the pan and remove. Dust with powdered sugar and serve with whipped cream.