Preheat your oven to 350°F (175°C) and line two large baking sheets with parchment paper.
In a medium bowl, whisk together the 1 1/2 cups gluten-free flour and 1/4 teaspoon salt until well combined; set this dry mixture aside.
In a large mixing bowl, use an electric mixer on medium speed to beat the 1 cup of softened butter, 1/2 cup powdered sugar, and 2 teaspoons vanilla extract until the mixture is smooth, pale, and fluffy, about 2-3 minutes.
Gradually add the dry flour mixture to the butter mixture, beating on low speed just until a soft dough begins to form, then use a spatula to fold in the 1 cup of finely chopped pecans until they are fully incorporated into the dough.
Scoop the dough by rounded teaspoonfuls and roll them between your palms into 1-inch balls; arrange the balls 2 inches apart on the prepared baking sheets.
Bake for 12-14 minutes, or until the bottoms are just lightly golden and the tops are still pale and look set; the cookies will be very soft.
Allow the cookies to cool on the baking sheet for 5 minutes, then while still warm, carefully roll each cookie in the remaining 1 cup of powdered sugar until fully coated.
Place the sugared cookies on a wire rack to cool completely, then roll them in powdered sugar a second time for a thick, snowy coating.
