Preheat oven to 180 degrees Celsius.
Beat soft butter and icing sugar until light and creamy. Add egg and
beat until well mixed. Fold in vanilla essence. Stir in sifted flour
until well mixed. Spoon mixture into a piping bag fitted with a star
shaped piping nozzle and pipe 4 cm circles of mixture onto
prepared baking tray. Press the centre of the circles. Place jam in
the centre of each circle. Bake for 20 minutes. Cool on wire rack.