Method

1. Place the whole unpeeled oranges in water, cover and bring to the boil. Simmer for 1½ hours or until soft, adding more water if necessary. Drain the oranges and cut in to quarters, remove any pips, and wizz in a blender (including peel), then leave to cool.

2. Heat oven to 180C, 160C(fan), Gas 4. Grease and line a 9” cake tin.

3. Beat the egg yolks and sugar together until pale. Beat in the cold oranges, almonds, and baking powder, and set aside. Beat the egg whites until they form soft peaks, then gently fold in to the mixture.

Bake for about an hour, until until golden and springy to the touch.