Melting Moments: Preheat oven to 160°C conventional. Line 2 oven trays with baking paper.
Using an electric mixer, beat butter and icing sugar until pale and fluffy. Sift in flour and cornflour and stir until combined.
Roll 2 tsp of mixture into a small ball and place on tray. Flatten with a lightly floured fork, making an indent. Repeat to make 36 biscuits.
Bake for 15 minutes or until golden. Transfer to a wire rack to cool.
Filling: Put strawberry, caster sugar and water in a saucepan over a medium heat and stir until sugar dissolves and it comes to the boil.
Simmer 2 minutes then pour syrup through a sieve into a jug and leave to cool. Discard strawberry pieces.
Beat butter and icing sugar until pale and fluffy. Add cooled strawberry syrup, 2 Tbsp at a time, beating continuously until smooth and soft.
Spread a little filling over 18 of the biscuits, then sandwich with remaining biscuits. Dust with extra icing sugar to serve.
Store in an airtight container for up to 1 week.
Tip: Swap strawberry syrup for 2 Tbsp fresh passionfruit juice.