Preheat oven to 350°F (175°C). Line baking sheets with parchment paper.
In a medium bowl, whisk together flour and salt. Set aside.
In a large bowl, cream together butter and confectioners' sugar until light and fluffy, about 3 minutes. Stir in vanilla extract until combined.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Fold in chopped pecans, if using.
Use a cookie scoop or heaping tablespoon to measure out dough and roll into 1-inch balls. Place balls on the prepared baking sheets, leaving about 2 inches between each cookie.
Bake for 11-12 minutes, or until the edges are set and the centers are still soft.
Let the cookies cool for about 5 minutes on the baking sheet. While still warm, roll each cookie in the confectioners' sugar until completely coated. Place cookies on a wire rack to cool completely.
Once completely cooled, roll the cookies in the confectioners' sugar again for a thicker coating, if desired.
Enjoy your delicious snowball cookies!