Heat the oven to 180°C / 350℉. Line a 12 hole cupcake pan with liners.
Beat the butter and sugar together until light and creamy, then add in the egg.
Beat in the milk and syrup/molasses/treacle until combined. Please note that at this point, the ingredients will look mottled rather than smooth.
In a separate bowl, mix the remaining dry ingredients and fold into the wet ingredients.
Drop into the cupcake cases (to around ½- ¾ full) and bake for 18-20 minutes. An inserted skewer will come out clean when they are ready. Leave to cool completely.