Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

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 to the butter mixture, mixing well to combine.

In a separate bowl, sift together the all-purpose flour and cornstarch.

Gradually add the flour mixture to the butter mixture, stirring until just combined. If the dough is too crumbly, add milk one tablespoon at a time until the desired consistency is reached.

Using a spoon or a piping bag, drop small mounds of dough onto the prepared baking sheet, leaving space between each mound to allow for spreading.

Bake in the preheated oven for 12-15 minutes or until the edges are lightly golden. The centers should remain soft.

Remove from the oven and allow to cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely.

Once cooled, you can dust the tops with additional icing sugar if desired.