Position an oven rack in the centre of the oven. Preheat to 180 C / Gas 4. Line a 25cm round cake tin with baking parchment.
In one bowl, combine the wet ingredients - treacle, sugar and oil. In another bowl, combine the dry ingredients - sifted flour, cinnamon, cloves and black pepper. Set aside.
Bring water to the boil in a saucepan, stir in bicarbonate of soda, then mix into the wet ingredients. Stir in the ginger.
Gradually beat the dry ingredients into the wet ingredients. Add eggs and continue beating until thoroughly combined. Pour into prepared cake tin.
Bake in preheated oven for 1 hour. The cake is done when the top springs back lightly when pressed or a skewer inserted into the centre comes out clean. NOTE: If the cake browns too quickly, drape a piece of foil over the top and continue baking.
Allow to cool for at least 30 minutes, then run a knife around the edge of the tin to loosen the cake. Turn out and remove the baking parchment.