Grease a tin, about 30 x 40 cm, and sprinkle with the sugar. Beat the eggs and sugar until fluffy. Stir in the margarine and water. Mix together the dry ingredients and fold into the mixture. Add your chosen flavouring. Pour into the pan and bake in the centre of the oven for 25-40 minutes at 175°C. Turn the cake out of the tin. Decorate the cake as desired.