Preheat your oven to 350°F (175°C) and prepare a 10-inch tube pan without greasing it.

In a large bowl, whip room-temperature egg whites until frothy. Gradually add granulated sugar, whipping until stiff peaks form.

Sift cake flour and a small amount of sugar together in another bowl. Fold this mixture into the whipped egg whites carefully.

Gently fold in the fresh raspberries without crushing them.

Pour the batter into the prepared tube pan and smooth the top with a spatula.

Bake for 30-35 minutes until the cake springs back when touched and a toothpick inserted comes out clean.

Invert the pan onto a wire rack and let the cake cool completely before removing.

Once cooled, dust with powdered sugar and serve slices with whipped cream and extra raspberries if desired.