This is utterly, utterly gorgeous - Nigella recommends a lemon icing, but it really doesn't need it.
150g unsalted butter
125g dark muscovado sugar
200g golden syrup
200g black treacle
2 teaspoons grated fresh ginger
1 tsp ground cinnamon
2 large eggs, beaten
1 tsp bicarbonate of soda, dissolved in 2 tbs warm water
300g plain flour
1 roasting tin 30x20x5cm, greased and lined with parchment or foil
Preheat oven to 170C/gas 3
Melt the butter with the sugar, syrup, treacle, ginger and cinnamon. Take off the heat, and add the milk, eggs and bicarb in water.
Place the flour in a bowl and pour in the liquid ingredients, beating well (it makes a very liquid batter, so don't be alarmed). Pour into the tin and bake for about 1 hour.