Preheat the oven to 170 deg C/gas mark 3
Coat the sliced apples in lemon juice to prevent browning and set aside
Beat together the margarine and sugar until pale and fluffy. Add the eggs with a little of the flour and beat until smooth.
Fold in the rest of the dry ingredients with a spatula
Stir in the yoghurt followed by the brandy.
Transfer the batter to a well greased 23cm cake tin.
Arrange the apple slices on the batter in a spiral pattern
Mix the demerara sugar and cinnamon together and sprinkle liberally over the top
Bake for around 40 minutes until a skewer comes out clean.
Leave to cool in the tin for 15 minutes before turning out onto a wire rack
Serve warm with non-dairy yoghurt as a dessert or cold as a cake.