Line a 20x30 cm (8x12in) baking pan with baking paper.
Put the sugar, flour, baking powder, salt, egg and butter in an electric mixer and mix until just combined.
Press the mixture into the base of the prepared pan and bake it in a pre heated oven at 180°C – 350°F for 20 to 25 minutes or until golden and firm. Let it cool completely.