Preheat the oven to
160 °C and line a 23cm x 13cm loaf tin with parchment paper.TIP: place a drop of oil or butter under the paper to stop it slipping Place a saucepan on low heat and melt together the butter, sugar, golden syrup and black treacle.Don't allow the mixture to boil. Sift the remaining dry ingredients into a medium mixing bowl.
Pour the saucepan contents into the dry ingredients and mix until just combined.
Add the milk and beaten egg, then beat until smooth. It will take on a glossy/shiny appearance when ready.
Pour into the prepared loaf tin. Smooth the top by gently shaking or using the back of a damp metal spoon.
Place in the centre of the oven and bake for 30-35 minutes or until a skewer inserted into the centre is clean when removed.
Allow the cake to cool in the tin for 10-15 minutes before transferring to a wire rack to cool fully.
Dust with icing sugar before serving.