Add the sugar, syrup and water to a pan and heat the ingredients until they start to bubble. Remove from the heat and allow to cool for a while.
Mix the spices together and along with the butter, add to the pan. Stir gently until the butter has melted.
Sift 425g of the flour and baking soda together and then add to the wet ingredients, stirring until a fairly sticky dough forms. If you need more flour, just add a little at a time (the dough firms up when chilled, so don't add too much, Although sticky, you should be able to mould it together with your hands). Form into a rough ball shape, cover with clingfilm (or place in a plastic bag) and leave in the fridge for at least 24 hours.
When you are ready to bake, pre-heat the oven to 200°C and divide the dough into three or four bits (it's easier to work with the dough in smaller quantities) and roll out on a floured surface. SEE NOTES