Step 1:Preheat the oven to 180C (fan 160C, gas mark 4) and grease and base line 2 x 20cm Victoria sponge cake tins.Step 2:Sift the flour into a bowl, stir through the baking powder, bicarbonate, salt, ground ginger and sugars. Stir through the stem ginger to coat in the flour mixture.Step 3:In another bowl mix together the eggs, parsnips, extract and butter. Pour onto the flour mixture and fold in well but don’t over mix.Step 4:Divide equally between the tins and spread out evenly to the sides. Bake in the preheated oven for 25 minutes until springy to the touch and coming away from the tins. Leave in the tins for a few minutes before turning out onto a cooling rack and cool.Step 5:Meanwhile make the icing by beating together the icing sugar, butter and ginger syrup until light and fluffy. Ice the top of one cake with half of the icing, then top with the other cake and finish using the remaining icing. Dust with icing sugar.