Preheat oven to moderately 180oC.
Brush two 32 x 28 cm biscuit trays with melted butter or oil, line bases with paper, grease paper.
Dust tins lightly with flour, shake off the excess. Mark lines in the
flour 7cm apart on each try.
Sift the flour three times onto
greaseproof paper.
Place egg whites in a small, clean,
dry mixing bowl.
Using electric beaters, beat until
firm peaks form.
Add sugar gradually, beating
constantly until dissolved and mixture is glossy and thick.
Add beaten egg yolks, beat a further
20 seconds.
Transfer mixture to large mixing bowl.
Using a metal spoon, fold in
flour
gradually and lightly. Add butter, fold through.
Place mixture in large piping bag
fitted with a round nozzle. Pipe fingers between the 7cm lines, leaving
5cm between each one.
Bake for 6 minutes or until lightly
golden. Leave sponge fingers on tins for 5 minutes before placing them
on wire rack to cool.
Beat cream and essence in small bowl
until stiff peaks form.
Sandwich two sponge fingers together
with a spoonful of whipped cream. Repeat with the remaining fingers and
cream.