METHOD

Preheat the oven to 180 deg/C. Grease a 23cm springform cake tin, (we used a Jamie Oliver).

Core 3 1/2 of the apples and cut them into small chunks. Slice the remaining apple into crescent-shaped wedges to decorate the top of the cake. Squeeze the lemon juice over the apples to stop them from going brown.

In a mixing bowl, beat the butter with the sugar, lemon zest, vanilla extract and salt until pale and fluffy. Add the eggs one at a time, beating well between additions until smooth. Beat in the yoghurt and the oil, then fold in the baking powder and the flour and finally the chopped apples. Mix together until you have a nice smooth batter.

Pour into the prepared tin, decorate with the apple slices and sprinkle over the extra sugar. Bake in the oven for 45-50mins until risen and golden, then insert a skewer (or spaghetti strand) to check it's done. Allow to cool for 10 minutes in the tin before turning out onto a wire rack.

Dust with icing sugar and serve warm or cool.