Preheat oven to 350°F. Line baking sheets with parchment paper.
In a large bowl, using a hand mixer, cream the butter with 1/2 cup of the confectioners' sugar and vanilla.
Starting on low speed, add the flour, pecans, and salt. Increase speed to medium until all ingredients are incorporated.
Use your hands to roll the dough into 1-inch balls. Place them on the lined baking sheet, leaving about an inch in between each cookie.
Bake for 10-12 minutes, or until golden brown. (You don't want them too brown.)
Remove cookies from the oven and while still hot, roll each in the remaining cup of confectioners' sugar. Set coated cookies back on the lined baking sheets to cool.
Once cool, roll the snowball cookies in the confectioners' sugar a second time. Store cookies in an airtight container at room temperature for up to 3 days.