1.Place unpeeled whole oranges in medium saucepan, cover with cold water; bring to the boil. Boil, covered, 1½ hours or until oranges are tender; drain. Cool.
2.Preheat oven to 180ºC/350ºF. Grease deep 22cm (9 inch) round cake pan; line base and side with baking paper.
3.Trim and discard ends from oranges. Halve oranges; discard seeds. Blend or process oranges, including rind, with baking powder until mixture is pulpy.
4.Beat eggs and sugar in medium bowl with electric mixer about 5 minutes or until thick and creamy. Fold in ground almonds, sifted flour and orange pulp.
5.Pour mixture into pan, sprinkle with nuts; bake about 1 hour. Cool cake in pan.
Store in an airtight container, in the refrigerator, for up to three days. Suitable to freeze for up to three months. Wash and dry the oranges well to get rid of any pesticides or waxy residue. Don’t roast the pine nuts before sprinkling; they will roast in the oven.