Preheat your oven to 325°F. Line a baking sheet with parchment paper.
In a large bowl or the bowl of a stand mixer with the paddle attachment, beat the softened butter, powdered sugar, and salt until light and fluffy, about 3-5 minutes.
Stir in the vanilla extract until fully incorporated.
With the mixer running on low, gradually add the flour and mix just until a soft dough forms and no dry streaks remain. If the dough looks crumbly and doesn’t hold together when pressed, mix in 1 teaspoon of water at a time until it comes together.
Fold in the chopped pecans until evenly dispersed.
Using a teaspoon of dough for each cookie, shape the dough into a crescent by gently rolling it between your palms. Place the crescents on the prepared baking sheet, spacing them about 1 inch apart.
Bake for 15-20 minutes, rotating the pan halfway through, until the cookies look dry on top and the bottoms and edges are a light golden brown. The tops should remain pale.
Let the cookies cool on the pan for 5 minutes—they’re fragile when hot.
While still warm but cool enough to handle, gently roll each cookie in powdered sugar to coat, then transfer to a wire rack.
Cool completely, 20 to 30 minutes. Roll in powdered sugar once more just before serving, if you like.