Preheat oven to 220degC/428degF/gas mark 7.Now In a saucepan, melt one tablespoon of butterCook the apple chopped for 5 minutes.
Add the cinnamon to the mixture and continue cooking for 2 more minutes.Leave it to cool.
Add the flour and salt to a medium-sized bowl.Mix the butter and crumbs until it resembles breadcrumbs.
Add the buttermilk, sugar, and apple to the bowl.Mix until all ingredients are well combined.
Now Place the mixture on a lightly floured surface. Knead the mixture until it forms a ball.
After this, Place the cake on a baking tray and use a knife to cut it into 8 pieces.Sprinkle demerara sugar on top.
Now Bake for twenty to twenty-five minutes, or until golden and risen.Let cool on a wire rack for fifteen minutes.Before serving, separate the wedges.