Pre-heat oven at 190°C
Grease and line a 20x20cm cake tin, ensure paper comes about 2cm above the top edge of the tin.
Whisk eggs by gradually adding sugar until thick and sugar is dissolved
Sieve and fold in flour, corn flour and baking powder
Pour into prepared tin and bake for 25-27 minutes
Invert the tin and cool on a wire rack
Once cooled trim the edges and cut the sponge into 4 squares
