In a large mixing bowl, cream together the softened butter and icing sugar until light and fluffy. Add the vanilla extract and a pinch of salt, mixing until well combined. Gradually add the all-purpose flour, mixing until a smooth dough forms. If the dough feels too soft, wrap it in plastic wrap and refrigerate for 30 minutes.

Preheat your oven to 180°C (350°F). On a lightly floured surface, roll out the dough to about 5mm (¼ inch) thickness. Using a star-shaped cookie cutter, cut out star shapes and place them onto a baking sheet lined with parchment paper.

Bake in the preheated oven for 20 minutes, or until the edges are lightly golden. Allow the cookies to cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.

While the cookies are cooling, melt the dark chocolate using a double boiler or microwave. If using a microwave, heat in 30-second intervals, stirring in between, until fully melted. Stir in the coconut oil if desired, to achieve a smoother finish.

Once the cookies have cooled completely, dip each one halfway into the melted chocolate, allowing any excess to drip off. Place the dipped cookies onto the wire rack and let them set. For a quicker setting, refrigerate the cookies for about 10 minutes.