To make the biscuits, beat butter, icing sugar, lime juice and vanilla paste with an electric mixer for 3 minutes, until pale and creamy
Sift flour and cornflour over the butter mixture and stir with a wooden spoon until well combined. Refrigerate 10 minutes to firm up slightly
Preheat oven to 160°C and line two oven trays with baking paper
Roll a heaped tablespoonful of dough into a ball, place on lined tray and press lightly with the tines of a fork to form a cross-hatch pattern on the top. Repeat with remaining dough to make 24 biscuits
Bake approximately 14 minutes until just golden. Cool briefly on trays, then transfer to a wire rack to cool completely
Lime Butter
Ingredients
225g icing sugar
75g unsalted butter, room temperature
30ml (1 1/2 tbsp) lime juice
Method
To make lime butter, beat all ingredients with an electric mixer for 3 minutes until pale and creamy
Top half the biscuits with lime butter and refrigerate 15 minutes to firm up. Top lime butter with a spoonful of cooled passionfruit curd and sandwich with remaining biscuits. Store sandwiched biscuits in an airtight container in the refrigerator for up to 3 days