1Preheat your oven to 170°C Fan. Line a 9 by 9 inch baking dish with parchment paper and set aside.
2Add the treacle, muscovado sugar, butter and golden syrup into a pot and stir on a low heat until completely melted.
3Add the self-raising flour, ground ginger, optional stem ginger, cinnamon, nutmeg, flaked salt, and fine oatmeal into a large mixing bowl and whisk to incorporate.
4Pour the melted syrup mixture into the dry ingredients and whisk along with the buttermilk and vanilla extract.
5Add the egg and whisk again until well combined.
6Pour the mixture into the prepared baking dish.
7Pop into the oven and bake for 50 minutes or until a wooden skewer inserted comes out clean.
8Leave to cool in the tin, and cut into 12 squares.
9Wrap the squares in tin foil. Keep for up to five days before eating if you can – it’ll become softer and stickier the longer you leave it.