Traditional Dorset apple cake

Method

1. Heat the oven to 160°C fan/gas 4 and butter the cake tin. In a large mixing bowl, rub the butter and flour together with your fingertips until the mixture resembles coarse breadcrumbs. Stir in the baking powder and a pinch of salt, then put the bowl in the fridge.
2. Put the caster sugar in another mixing bowl. Peel, core and chop the apples into bite-size pieces, adding them to the sugar and tossing as you go. When all the apples are chopped, give the fruit a good stir so any sugar at the bottom of the bowl is distributed over the fruit. Tip the sugary apples into the flour mixture, then stir in the yogurt/soured cream and vanilla extract. This will create a thick batter (it will seem like there is more apple than batter).
3. Pour the batter into the prepared tin, pushing it to the edges and spreading it out evenly. Smooth the top, then sprinkle with the demerara sugar. Bake for about 40 minutes, or until golden and a skewer pushed into the centre comes out clean. Leave the cake in the tin for 10 minutes before turning out onto a wire rack to cool completely