Preheat oven to 165°C (325°F). Line 2 baking sheets with parchment paper.

In a large bowl, beat the softened butter and granulated sugar together on medium-high speed until light, pale, and fluffy.

Add the salt and the egg to the butter mixture. Beat until well incorporated, then mix in the vanilla extract.

Turn the mixer to low speed and add the all-purpose flour. Mix until just combined to ensure the cookies remain tender—do not overmix. The dough should be soft and easy to pipe.

Transfer the dough into a large piping bag fitted with a large open star nozzle. Pipe the dough onto the prepared baking sheets in circles or swirls, spacing them about 1/2 inch apart.

Sprinkle a little granulated sugar over the top of each piped cookie for the classic finish.

Bake for approximately 15 minutes, or until the cookies are a light golden brown.

Let the cookies cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.