Set oven to 220*c/fan oven 200*c/Gas mark 7. Place the oats, wholemeal flour, sugar and salt in a bowl. Sift in the baking soda and self raising flour.

Melt the treacle and butter together and cool to room temperature. Make a well in the centre of the dry mixture and add the treacle mixture and buttermilk.

Mix to a loose dough. Turn onto a floured surface. Knead lightly into a ball and transfer to a floured baking tray.

Flatten slightly and make a cross in the centre with a knife.

Bake at 220*c for 10 minutes then lower the heat to 140*c for a further 40 minutes or until the bottom of the loaf sounds hollow when tapped.

Cool on a wire rack.