Preheat oven to 180 C / Gas mark 4. Grease baking trays.
In a large bowl, beat the eggs and sugar until light and fluffy. Stir in the oil, vanilla and orange juice.
Combine the flour and baking powder; stir into the egg mixture to form a stiff dough. If dough is not stiff enough to roll out, stir in more flour. On a lightly floured work surface, roll dough out to .5cm (1/4 in) in thickness. Cut into circles using a pastry cutter or the rim of a drinking glass. Place circles 5cm (2 in) apart onto the prepared baking trays.
Spoon about 1 dessertspoon of preserves into the centre of each circle. Pinch the edges to form three corners.
Bake for 12 to 15 minutes in the preheated oven, or until lightly browned. Allow biscuits to cool for 1 minute on the baking tray before removing to wire racks to cool completely.