Preheat oven to 180 degrees C. Lightly grease two 30 × 22 x 2 cm baking tins.
Mix all the dry ingredients, except the baking soda. Place the golden syrup, water, oil and butter in a saucepan and heat on the stove until the butter and syrup have melted. Remove from the heat and stir in the baking soda. Add the syrup mixture to the dry ingredients and mix well.
Spoon mixture into the baking tin, pressing it down firmly and evenly (it should be about 7mm high). Bake for 20 minutes or until golden around the edges.
Remove from the oven; leave in tin to cool slightly. Using a sharp knife, cut each tin into 40 equal pieces. When almost cool, turn out onto a wire rack to cool completely.