1. Preheat the oven to 170°C (340°F (171°C)).
2. Line a 23cm (9-inch) square baking tin with foil and grease it lightly.

1. In a saucepan, melt the butter, golden syrup, dark muscovado sugar, and Guinness over low heat.
2. Stir in the ground ginger, cinnamon, and cloves.
3. Remove from heat and whisk in the flour and bicarbonate of soda until smooth.
4. In a separate bowl, whisk together the sour cream and eggs, then incorporate into the gingerbread mixture, ensuring a lump-free batter.
5. Pour the batter into the prepared tin and bake for about 45 minutes, until the centre is risen and the edges pull away from the sides.

Allow the gingerbread to cool in the tin before cutting into squares or slices for serving.