In a large bowl, mix the flour, butter, powdered sugar, pecans, vanilla extract, and salt until a soft, cohesive dough forms. Transfer to the freezer for 10 minutes to firm slightly.

Lightly flour a work surface and roll the dough into a thick rectangle about ¾-inch thick. Cut into small cubes and arrange on the prepared baking sheet, spacing slightly apart.

Bake until the cookies are set and pale, 14 to 15 minutes. They should not brown. Let cool on the baking sheet for 20 minutes.

Place the powdered sugar in a deep bowl. Gently coat the cookies while still slightly warm, then transfer to a wire rack or tray and let cool completely.

Store in an airtight container at room temperature for up to 1 week.