Preheat oven to 180°C. Line two oven trays with baking paper.
In a large bowl or bowl of your stand mixer, use electric beaters to combine butter and sugar. Add egg, lemon zest and juice and salt and beat to combine.
Use a spatula to fold in Lemon Drop Cookie Mix. Measure out tablespoon amounts of mixture and roll into balls. Place on lined oven tray about 7cm apart.
Bake cookies for about 10 minutes, until slightly golden at the edges. Once cooked, use the back of a spoon measure to press down the centre of the cookie to make a small indent.
Allow cookies to fully cool before adding a dollop of lemon curd to the centre.