Ingredients

2 oranges, about 280g, scrubbed and roughly chopped (with skin), pips discarded

5 eggs, separated

200g caster sugar

220g ground almonds

2 tablespoons flaked almonds

icing sugar, sifted, to decorate

Preparation

1. Place the chopped oranges in a small saucepan. Add 1 tablespoon water, then cover the pan and simmer gently for 30 minutes or until the oranges are soft and all the excess liquid has evaporated. Leave to cool.

2. Preheat the oven to 180ºC. Line the bottom and sides of a 23 cm springform cake tin with baking paper. Finely chop the oranges in a food processor or blender, or with a sharp knife.

3. Place the egg whites in a large bowl and beat with an electric mixer until they form stiff peaks. Gradually add half the caster sugar, then beat for 1 minute.

4. Place the egg yolks and the remaining caster sugar in another bowl and, using the same beaters, beat for 2–3 minutes or until pale and quite thick. Add the oranges and beat to combine well. Carefully fold in the ground almonds with a large metal spoon.

5. Stir in 3 spoonfuls of the egg whites to loosen the mixture, then gently fold in the remaining whites. Transfer the mixture to the tin and level the surface. Sprinkle with the flaked almonds.

6. Bake for 50–55 minutes or until the cake is golden and a skewer inserted in the centre comes out clean. Check the cake after 20 minutes and again at 30 minutes, and cover lightly with aluminium foil if it is browning too quickly.

7. Leave the cake to cool in the tin, then turn it out, peel away the lining paper and transfer to a serving plate. Dust with icing sugar before serving. The cake can be kept in an airtight container for up to 2 days.