Preheat oven to 175 degrees C. Lightly grease a 9" springform (loose bottomed) round pan

Wash the oranges thoroughly - do not peel them! Yes we will be using the whole fruit, peel and all, except the seeds! Cut off the top and bottom ends and discard. Chop up the rest of the fruit (if you are using the seeded variety, makes sure you remove the seeds).

Pulse the chopped fruit in a blender or mixer grinder till it is thick and coarse and has some texture to it. Then add the olive oil and blend again till you get a fairly smooth mixture. Place the mixture in a mixing bowl.

Sift together the flour, salt, baking powder and baking soda and add this in parts to the orange-olive oil mixture.

In an another bowl beat the eggs till fluffy, then add in the sugar and beat some more.

Gently add the egg mixture to the orange-flour mixture and fold until incorporated. Make sure that you neither beat the mixture nor mix vigorously or it will deflate the eggs and make the cake very dense.

Pour the batter into the prepared tin and bake for about 50-60 minutes or till the skewer inserted comes out clean.

Remove and cool the cake in its tin for 10 minutes, then gently invert onto a wire cooling rack till completely cooked.

Dust with icing sugar, decorate with orange slices and serve!