JAM HEART BISCUITS:
250g unsalted butter, at room temperature
1 cup icing sugar, sifted
1 tsp vanilla extract
3¼ cups plain flour
1/3 cup cornflour
½ cup raspberry or strawberry jam
2 tbs icing sugar, extra
Using an electric mixer, beat butter, icing sugar and vanilla in a large bowl until pale and creamy. Add egg and beat until well combined. Sift flour and cornflour together over butter mixture and stir in until dough comes together. Divide dough in half and flatten to make 2 discs. Wrap in baking paper and refrigerate for 30 minutes.
Preheat oven to 160°C. Line 2 large baking trays with baking paper. Roll out 1 dough disc until 4mm thick. Using a fluted 6cm round biscuit cutter, cut out 20 rounds. Using a small heart-shaped biscuit cutter, cut out a heart from the centre of each biscuit. Place onto a prepared tray. Roll out remaining dough and cut out 20 round biscuits. Place onto other tray. Bake for 15-20 minutes or until pale golden and firm to the touch. Transfer to a wire rack to cool.
Place round biscuits onto a flat surface. Spread each with 2 tsps of jam. Dust biscuits with heart centre with extra icing sugar and then sandwich biscuits together.
Store in an airtight container.