Preheat your oven to 150°C (fan 130°C) or Gas Mark 2. Grease and line a 20 cm square baking tin with parchment paper, ensuring the paper comes slightly up the sides for easy lifting later.

In a saucepan, gently warm the butter, golden syrup, treacle, and brown sugar over a low heat until smooth. Stir occasionally, but do not let the mixture boil. Remove from the heat once combined.

In a large bowl, combine the oatmeal, flour, baking powder, ground ginger, cinnamon, and nutmeg. Mix thoroughly to distribute the spices evenly.

Pour the warm syrup mixture into the bowl of dry ingredients. Stir gently with a wooden spoon until just blended, avoiding over mixing to keep the texture soft.

Stir in the beaten egg and milk until you have a thick, smooth batter. Scrape down the sides of the bowl to ensure all the dry bits are incorporated.

Pour the batter into the prepared baking tin. Smooth the surface with the back of a spoon so the cake bakes evenly.

Place the tin on the middle shelf and bake for 50 to 60 minutes. The cake should feel springy in the centre and a skewer inserted should come out mostly clean.

Remove from the oven and allow to cool in the tin for 15 minutes. Lift out carefully using the parchment and set on a wire rack to cool completely.

Wrap the cooled cake tightly in parchment or foil and leave for at least 24 hours before eating. This resting time allows the cake to become wonderfully sticky and enhances the ginger flavour.

Cut into squares and serve with a cup of tea or as a comforting dessert with custard. A light dusting of icing sugar is optional but makes a charming finish.