1. Place the clean,whole and unpeeled oranges in water to cover and bring to the boil. Simmer for 1½ hours or until soft,adding more water when necessary.
2. Drain the oranges,cut into quarters,discard any major pips,and whiz the rest,including peel,in the food processor,then cool.
3. Heat oven to 180C. Beat the egg yolks and sugar together in a large bowl until pale. Beat in the oranges,almonds and baking powder.
4. Beat the egg whites until softly peaky and fold gently into the mixture.
5. Pour into a high-sided 23cm springform cake tin and bake for 1 hour,until firm to the touch (cover with a loose sheet of foil if over-browning). Cool in the tin. Dust with icing sugar to serve.
Blueberry compote
Place 300g blueberries,50g castor sugar and 50ml Cointreau or similar in a heatproof bowl set over a pot of barely simmering water for 20 minutes,tossing occasionally,until the fruits drop their juices. Serve with orange and almond cake,panna cotta or ice-cream for a fast but stylish dessert.