Preheat the oven to 160°C/320°F, static mode (top and bottom heat).

In a large bowl, whisk the yolks with oil until combined. Add ½ cup/100 grams sugar and whisk until smooth.

Add half the flour and half the orange juice alternately, whisking well. Stir in the remaining flour, baking powder, and orange juice until smooth and lump-free.

In a clean mixing bowl, whip the egg whites at medium speed until soft foam forms. Gradually add the remaining 1 cup/ 200 grams sugar and whip on high until glossy and stable peaks form.

Gently fold one-third of the egg whites into the yolk mixture. Fold in another third until fully incorporated. Fold in the final third carefully, ensuring a smooth, lump-free batter.

Pour the batter into an un-greased 26 cm/10-inch Dutch oven or tube pan, filling about ¾ full. Smooth the top and bake for 1 hour 10 minutes. Do not open the oven before one hour.

When golden and springy to the touch, remove from the oven. If using a Dutch oven pan, invert immediately onto the small legs. Allow to cool for 3 hours or overnight.

Once completely cooled, release the cake carefully using a small plate. Transfer to a serving plate and dust with powdered sugar.