Cream the softened butter and sugar (sachet 1) with an electric mixer until light and fluffy. Add the yolk and mix until combined. Add the cookie mix (sachet 2) mix to form a smooth, firm dough – you will need to use your hands to bring the dough together.

Roll out the dough between two sheets of baking paper to about 4mm thick. Place on a tray and chill in the fridge for 30 mins -1 hour until firm.

Preheat the oven to 160°C fan-assisted convection and line an oven tray with baking paper.

Cut out snowflakes (or other Christmas shapes) from the cookie dough and place on the prepared tray. Lightly whisk the egg white until broken down and frothy. Brush a thin layer of egg white over each cookie and sprinkle with white sugar.

Bake the cookies for 10-12 minutes or until golden and crisp. Allow to cool on the tray, then transfer to a large cookie jar or airtight container.

Tip: Brushing egg white over the cookie before baking gives them a lovely crackled texture.  For a smoother finish, you can leave out this step and just sprinkle over castor sugar.