Line two muffin, or individual rectangular cake tins (as pictured) with baking paper.
Preheat oven to 170 C.
Put the whole oranges into a medium saucepan. Cover with water and put on to boil. Once boiling, reduce heat, cover, and allow to simmer for 1 hour. Remove and allow to cool slightly.
Chop the oranges and place in a food processor. Pulse until smooth. Set aside.
Beat the eggs with the sugar until thick (about 8 minutes). Add the almond meal, baking powder, vanilla and orange puree and mix to combine.
Spoon the mixture into the prepared tin and place in the oven. Bake for 25 minutes or until when touched the cakes spring back. Allow to sit for 30 minutes before removing from the tin and allowing to cool on a wire rack.
Dust with icing sugar and serve.
