Preheat oven to moderated 180oC.
Brush two shallow, 20cm round sandwich tins with melted butter or oil.
Line bases with paper, grease the paper. Dust the tins lightly with
flour, shake off excess.
Sift the flour three times onto
Combine eggs and sugar in medium
heatproof mixing bowl. Place bowl over pan of simmering water.
Beat until mixture is thick and pale
yellow. Remove from heat, continue to beat until mixture has cooled
slightly and increased in volume.
Add flour, melted butter, lemon and
orange rind. Using metal spoon, fold quickly and lightly until
ingredients are just combined.
Spread mixture evenly into prepared
tins. Bake for 20 minutes or until the sponges are lightly golden and
shrink from sides of tins. Leave sponges in tins for 5 minutes before
turning onto wire rack to cool.
To make Lemon Curd Filling -
Combine cornflour, sugar, milk, lemon juice and eggs in small pan, mix
well. Stir over low heat until mixture boils and thickens, cook for 1
minute longer. Remove from heat. Transfer to a small bowl, cover with
plastic wrap and allow to cool before using.
Cut each cake in half horizontally.
Place a cake layer on a serving plate. Spread the cake evenly with the
filling. Continue layering with remaining cake and filling, ended with a
cake layer on top. Dust the top with sifted icing sugar, if desired.