1. Grease a 23 cm dish. Combine butter, sugar and water in a large bowl.
2. Cook on high for 4 minutes in the microwave. Cool to room temperature.
3. Sift dry ingredients into butter mixture, beat with wooden spoon until smooth.
4. Pour mixture into prepared dish, cook on high for approximately 10-12 minutes, or until cake feels firm.
5. Stand 5 minutes before turning onto wire rack to cool.
6. Sift a little dry icing sugar on top (optional).

Serves: 7 to 8