Preheat the oven to 180 ºC (350 ºF).
Spray a 20 cm, loose-bottomed cake tin with non-stick spray.
Boil the whole orange until soft.
Dunk in cold water and halve.
Remove the pips.
Mince the entire orange or process in a food processor.
Whisk the eggs until light and fluffy.
Add small quantities of the sugar at a time while beating continuously.
Add the baking powder and almonds and fold in.
Add the orange purée and fold in.
Turn into the prepared cake tin and bake for 45 to 60 minutes or until a testing skewer comes out clean when inserted into the centre of the cake.
Cool slightly in the tin before removing to cool completely.
Dust with icing sugar just before serving.
COTTAGE CHEESE MIXTURE:
Beat the cottage cheese and sugar together, add the lemon juice and rind, and mix. Serve with the cake.