Preheat the oven to 350°F (175°C) and do not grease the tube pan.

In a mixing bowl, whisk egg whites until soft peaks form, then gradually add sugar and continue whisking until glossy peaks form.

In another bowl, mix together the cake flour, sugar, baking powder, and salt.

In a separate bowl, beat egg yolks, oil, orange juice, and vanilla extract together until smooth.

Gradually add the dry mixture to the yolk mixture, stirring until combined.

Gently fold the beaten egg whites into the batter until just combined.

Pour the batter into the ungreased tube pan and smooth the top.

Bake for 30-35 minutes or until a toothpick inserted comes out clean.

Once baked, invert the pan on a bottle neck or similar to cool upside down.

Once completely cool, run a knife around the edges, and gently remove the cake from the pan.

Serve plain or with a light drizzle of orange glaze or whipped cream.