Golden Syrup Slice/Cake

Preheat the oven to 180 C.  Grease a cake tin  20 x 20 or 20 x 30 cm, then line with baking paper.Sift the flour and bicarbonate of soda into a bowl.Put the golden syrup, oil and sugar into a saucepan.  Stir over low heat until the sugar dissolves, about 3 - 4 minutes.  Allow to cool.Add the syrup and warm water to the dry ingredients.  Stir until well combined.  Pour into the prepared tin and bake for 45 minutes or until golden.  Allow to cool in the tin for 5 minutes before turning onto a wire rack to cool completely.For the icing, sift the icing sugar into a heat proof bowl.  Add the citric acid and enough cold water to make a stiff paste (a very small amount).  Place the bowl over a saucepan of simmering water and stir until thin enough to spread.  Spread the icing over the cold cake.If making it as a slice, cut into slices once set.