Heat the oven to 180 C / Gas 4. Grease and line a baking tray.
Mix self-raising flour, wholemeal flour, cinnamon and bicarbonate of soda. Stir in ground walnuts.
Beat the egg, brown sugar and oil in a bowl; stir in yogurt. Pour this wet mixture into the dry flour mixture; mix to form a soft dough. Place spoonfuls of the dough on the prepared baking tray.
Bake in oven for 45 minutes until risen and golden brown.
Transfer to a wire rack to cool, then pull apart to serve.