Grease a 15 112 x 10 1/2 x 1″ cake tin, line with wax paper and grease the paper.
Sift flour with baking powder and salt. Beat the eggs for approximately ten minutes until very thick and gradually add the sugar. Add the water with vanilla and carefully fold in the dry ingreedients. Pour into tin and bake for 15 mins. Before cooling, remove sides of sponge from tin with a knife and turn out onto a damp cloth or a dry one sprinkled with confectioners’ sugar. Carefully remove paper and cut off edges with a sharp knife. Roll up sponge in the cloth and allow to cool. Unroll, spread with desired filling, roll up again and decorate. Serves 8.