1 tsp baking powder
陆 tsp bicarbonate of soda
25g/1oz demerara sugar
1 tsp fine sea salt
300g/10陆oz coarse wholemeal flour, plus extra for the tins
30g/1oz salted butter, plus extra for the tins
700ml/1录 pint buttermilk
1 free-range egg, lightly beaten
butter or smoked salmon, to serve (optional)