In the bowl of an electric mixer, beat the butter and sugar together until creamy. Add the egg and vanilla and beat them through.

Add the rest of the dry ingredients to the bowl and beat them through too until the dough comes together.

Remove half the dough from the bowl and set it aside. Add the food colouring to the dough left in the bowl and beat it until the colour is even.

Lay two big sheets of baking paper on the bench and place a ball of dough on each one.

Lay a sheet of baking paper over the top of the dough and roll each one out into a large rectangle.

Place the pink dough on top of the white dough.

Trim the doughs so they form a perfect rectangle and then very gently, from the long side, roll them together using the baking paper as a lifter.

Keep the off-cuts and use them to make marble cookies.

Pour the sprinkles onto a large tray and roll the dough log in the sprinkles.

Wrap the dough in plastic wrap and refrigerate it, resting in two glasses, for at least 2 hours. Alternatively the dough can be frozen for later use.

Pre-heat the oven to 160C (320F) fan-forced and line two baking trays with baking paper.

Cut the dough into 1cm thick pieces and place each slice on the lined tray leaving at least 2cm between each one.

Bake the cookies for 8-10 minutes or until they start to turn golden at the edges.

Leave them to rest on the trays for 5 minutes and then transfer to a wire rack to cool completely.