In a large mixing bowl, use a hand mixer or a stand mixer fitted with a paddle attachment to beat the softened butter on medium speed until it becomes smooth and creamy, about 1 minute. Gradually add the confectioners’ sugar and continue mixing at medium-high speed until the mixture turns fluffy and well-combined. Be sure to scrape down the sides and bottom of the bowl to incorporate all ingredients. Add the vanilla extract, beating on medium-high until fully blended.

Lower the mixer speed and gradually incorporate the flour and salt. Initially, the dough will appear dry, but continue mixing; the flour will eventually bind with the butter mixture. Once all the flour is added, increase the mixer speed to high until the dough comes together. If desired, fold in the chopped pecans for added texture.

Cover the dough securely and refrigerate for at least 30 minutes, or up to 3 days. If the dough chills for more than 3 hours, allow it to rest at room temperature for at least 30 minutes before shaping, as it will firm up significantly in the refrigerator.

Preheat the oven to 350°F (177°C) and prepare two large baking sheets by lining them with parchment paper or silicone baking mats. Pour the confectioners’ sugar for the coating into a shallow bowl.

Using a tablespoon (about 20g) of dough for each cookie, shape the dough into small balls and place them on the prepared baking sheets, ensuring they are spaced at least 2 inches apart. Bake for approximately 15 minutes, or until the bottom edges are golden and the tops are just beginning to color.

Coating: Allow the cookies to cool on the baking sheet for about 5 minutes. While still slightly warm, carefully roll each cookie in the confectioners’ sugar, coating thoroughly. Transfer the coated cookies to wire racks to cool completely. The initial layer of sugar may melt and become slightly sticky—this is normal. Once the cookies are fully cooled, roll them in the confectioners' sugar a second time for a snowy, sweet finish that clings perfectly to the surface.

For optimal freshness, store the cookies in an airtight container at room temperature for up to one week.