Cut the oranges in halves. Remove all the
flesh, taking care not to break the skins. Liquidize the flesh for a
moment, then strain off the juice, discarding the pulp. Separate the
eggs. Mix the flour, sugar, 8 tbsp orange juice. Cointreau, milk and egg
yolks in a bowl. In a separate bowl, beat the egg whites until they form
peaks, then fold them into the orange mixture. Spoon into the orange
skins and cook in a hot oven (210C, 425F, Gas 7) for 12-15 minutes.
Serve immediately, sprinkled with icing sugar.