Step 1

Preheat oven to 160C/140 fan. Grease two oven trays; line with baking paper.

Step 2

Beat butter, vanilla and sifted icing sugar in small bowl with electric mixer until pale and fluffy. Transfer mixture to a large bowl; stir in sifted flour and cornflour in two batches.

Step 3

With lightly floured hands, roll rounded teaspoons of mixture into balls (you should have 40 balls); and place about 2.5cm apart on trays. Flatten slightly with a floured fork into 4cm rounds.

Step 4

Bake about 15 minutes or until biscuits can be pushed gently without breaking. Leave biscuits on trays for 5 minutes before transferring to wire racks to cool.

Step 5

Make buttercream.

Step 6

Sandwich biscuits with buttercream. Just before serving dust with sifted extra icing sugar.

Step 7

Beat butter, sifted icing sugar and rind in small bowl with electric mixer until pale and fluffy. Beat in juice until combined.