Heat the oven to 350°F (175°C) and line baking sheets with parchment paper. Make sure the butter is soft enough to beat easily but is not greasy, shiny, or melted.

Beat the softened butter and granulated sugar for 2–3 minutes, until the mixture is smooth, pale, and fluffy. This step helps create a light texture and gives the dough enough structure for piping.

Add the egg and vanilla extract, then beat until fully incorporated. Scrape down the sides of the bowl so the mixture is evenly blended.

Whisk the flour and fine salt together in a separate bowl. Add the dry ingredients to the butter mixture in batches, mixing only until a soft dough forms.

Transfer the dough to a piping bag fitted with a large open-star tip. Pipe 1 1/2–2-inch rosettes, rings, or short finger-shaped cookies onto the prepared baking sheets, or shape the dough by hand if it is too firm to pipe.

Sprinkle the piped cookies with coarse sugar, pearl sugar, or finely chopped nuts if desired. If the dough looks soft or the shapes lose definition, chill the piped cookies for 20–30 minutes before baking.

Bake each tray for 10–12 minutes, rotating the sheet once if needed. Remove the cookies when the edges are lightly golden while the centers remain pale.

Let the cookies cool on the baking sheet for 5 minutes, then transfer them to a wire rack. Store them in an airtight container only after they are completely cool.