Boiled Fruit: Place the dried apricots, stewed apples and water in a saucepan. Simmer for 5 minutes or until the apricots have softened.
Cake: Preheat oven to 180 degrees C. Lightly grease and line with baking paper a 23cm round tin.
Transfer the fruit mixture to a blender or food processor. Add the butter, oil and buttermilk then process until smooth. Leave the mixture to cool slightly then add the eggs, vanilla essence and orange zest, blending just until smooth. Transfer to a large bowl and stir in the sugar.
Sieve the flour, baking powder and bicarbonate of soda into a bowl. Fold the flour mixture into the apricot mixture in 3 batches. Fold in the apricots.
Pour the mixture into the prepared tin. Bake for 90 minutes or until a skewer inserted in the centre comes out clean. Remove from the the oven and leave to cool in the tin for 10 minutes. Turn out onto a wire rack to cool completely.