Preheat the oven to 150C/300F/gas mark 2
Use a 33 x 25cm/13 x 10 inch cake tin.
Grease and line the cake tin. Whisk the sugar and soya milk together. Beat in the oil and syrup, then fold in the flour and baking powder. Addthe ground ginger to the creamed mixture, with the mixed spice and chopped glacé ginger. Pour the mixture into the prepared tin. Bake in the preheated oven at for about 1 hour until well risen and firm to the touch. Allow the cake to cool in the tin. When cold, turn out of the tin and carefully remove the paper.
Icing: Mix the icing sugar and hot water together until smooth. Pipe the icing in a lattice pattern over the cake and decorate with pieces of crystallised ginger.