Whisk softened butter and icing sugar till fluffy. Add in vanilla essence and egg yolk.

Sift in flour gradually mixing into a firm dough.

Roll out into 4 mm sheets and using a cutter or glass, cut out round buscuit size discs (bases). Take half of the buscuits and cut a further hole in the middle (tops). Place on greaseproof baking tray and bake at 170°F for approx 10 mins or untill golden.

Remove from oven and leave to cool. When cooled, spread the whole buscuit bases with the jam, and place the buscuit tops with the holes on top to form a sandwich. Enjoy!