For preparing easy orange cake, place oranges in a saucepan of cold water. Bring to a boil. Boil gently for about 1 hour or until very soft. Drain. Cool slightly.
2)Preheat oven to 180C. Grease an 8-hole mini loaf pan (125ml capacity). Line the base and sides with baking paper.
Trim the ends of oranges. Quarter and remove any pips or excess pith. Process until smooth. Add caster sugar. Process until smooth. Add egg. Process until combined. Add hazelnut meal. Process until combined.
Divide mixture among prepared pan holes. Cook for about 35 minutes or until golden brown and cooked through.
Meanwhile, to make the mandarin syrup, stir sugar and water over a medium heat until sugar dissolves. Add mandarin juice and zest. Simmer mixture for about 20 minutes or until thickened to a syrup.