1. Gather all ingredients: butter, powdered sugar, flour, vanilla extract, salt, and optional cornstarch.
2. Preheat the oven to 300°F (150°C) and prepare a baking sheet with parchment paper.
3. In a large mixing bowl, whip the butter and powdered sugar using a stand or hand mixer until light and fluffy.
4. Add vanilla extract and mix until well combined.
5. In a separate bowl, whisk together the flour, salt, and cornstarch (if using).
6. Gradually add the dry ingredients to the butter mixture, mixing until a soft dough forms.
7. Cover the dough and chill it in the refrigerator for at least 30 minutes to prevent spreading.
8. Once chilled, scoop small portions of dough and roll into balls.
9. Arrange the dough balls on the prepared baking sheet, leaving slight space between each.
10. Gently press each dough ball with a fork to create a slightly flattened shape.
11. Decorate with sprinkles, nonpareils, or a candied cherry on top if desired.
12. Place the baking sheet in the preheated oven and bake for about 18-20 minutes or until the edges are set but not browned.
13. Remove the cookies from the oven and let them cool on the baking sheet for a few minutes.
14. Transfer the cookies to a wire rack to cool completely before serving.
15. Store in an airtight container at room temperature for several days to maintain freshness.