4 eggs, at room temperature
2/3 cup caster sugar
1 cup plain flour
Grease a 22cm round cake pan. Line base and side with baking paper, extending paper 2cm above pan edge.
Beat eggs and sugar in a small bowl of an electric mixer for about 10 minutes, or until thick and pale. Transfer to a large bowl.
Sift flour twice onto a sheet of baking paper. Sift again over egg mixture. Using a balloon whisk, gently fold to combine. (Don’t stir.) Pour into prepared pan.
Cook in a moderate oven (180C) for about 25 minutes, or until edge of sponge has shrunk slightly away from side of pan. Stand in pan for 5 minutes. Turn out onto a wire rack to cool.
Serve sponge topped with whipped cream, blueberries and sifted icing sugar (optional).