Preheat the oven to 180C (gas mark 4). Butter the bottom and sides of a 23cm springform or round cake tin with 5cm sides and line the bottom with a circle of parchment paper.
In a food processor fitted with the metal blade or with a chef's knife, chop the ginger until very fine. Set aside.
In a large bowl, mix together the golden syrup, sugar, and oil. In a medium bowl, whisk together the flour, cinnamon, cloves, and pepper.
In a small saucepan, bring the water to a boil, then stir in the bicarbonate of soda. Whisk the hot water into the golden syrup mixture, then add the chopped ginger. Gradually sift the flour mixture over the golden syrup mixture, whisking to combine. Add the eggs and whisk until thoroughly blended.
crape the batter into the prepared springform or cake tin and bake until the top of the cake springs back when lightly pressed with a finger or a toothpick inserted into the centre comes out clean, about 1 hour. Leave to cool completely. Run a knife around the sides of the cake to help loosen it from the tin. Invert the cake onto a plate, peel off the parchment paper, then re-invert it onto a serving platter.