Grease and line with parchment a 7 inch square baking dish or large loaf pan.

Sift flour, salt, spices, and baking soda in a bowl.

Add the oats, and mix well. 

Create a well in the middle of the dry ingredients.

Add treacle, milk, butter, and brown sugar in a pot. Stir over a low heat until the butter melts and the sugar dissolves.

Pour the liquids into the well in the dry ingredients, add the egg, and stir until combined.

Pour batter into the prepared baking dish, and cook at 180C for 60 minutes or until a skewer comes out clean.

Cool in the dish for at least 10 minutes, turn out onto wire cooling rack and allow to cool. Once cool, wrap in foil or keep in an airtight container.