In a large mixing bowl, beat the softened butter and sugar together until light and fluffy, about 2–3 minutes.
Mix in the egg and vanilla extract, scraping down the sides of the bowl as needed.
In a separate bowl, whisk together flour and salt. Gradually add the dry ingredients to the wet mixture and beat until a soft dough forms. Do not overmix.
Wrap the dough in plastic wrap and refrigerate for 30 minutes if you want sharper cookie shapes. This step is especially helpful for piped cookies.
Preheat oven to 350°F (175°C) and line baking sheets with parchment paper. Either roll the dough into small balls and flatten gently, or use a piping bag with a star tip to pipe rosettes or lines onto the sheet.
Bake for 10–12 minutes, or until the edges just start to turn golden. Do not overbake. Let cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.
Once cooled, dip the ends in melted chocolate and add sprinkles, or dust with powdered sugar for a classic look.