- Preheat oven to 160°C. Grease a 22cm square tin and line with greaseproof paper. Melt the butter, golden syrup, treacle and sugar gently in a heavy-bottomed pan. Allow to cool.
- Sieve together the plain flour, sea salt, ginger, cinnamon and bicarbonate of soda. Pour contents of pan into the flour.
- Beat in the egg and sour milk. Mix together to a smooth consistency. Pour the mixture into the prepared baking tin.
- Bake for about 60 - 85 minutes or until firm to touch. Turn out of tin onto a wire rack to cool.