Set oven racks to upper and lower thirds of the oven and preheat to 350F. Line two baking sheets with parchment paper or silpat and set aside.

In a small bowl, toss pecans and flour. Set aside.

In the bowl of a stand mixer fitted with the paddle attachment, beat butter on medium speed until smooth. Scrape down sides of the bowl and add confectioners sugar. Beat on low until light and fluffy, about 2 minutes.

Scrape down sides of the bowl again, and add flour-pecan mixture. Beat on low speed until well combined, at least 1 minute. The dough will be dry and will not come together, but rather, be in small clumps.

Use a 1 1/2 Tbs. cookie scoop to portion out dough onto clean hands. Gently roll dough into a ball, placing on prepared baking sheet at least an inch apart. After all dough is portioned out, press the tops of each cookie gently, flattening into a 2-inch disc.

Bake in preheated oven for 14-16 minutes, rotating halfway through. Cookies are ready when they're set and starting to brown on edges.

Remove from oven and allow to cook on baking sheets for 5 minutes, before moving to wire racks to cool completely. Once cooled, if desired, use a fine mesh sieve to dust cookies with additional confectioners sugar (you won't need more than a tablespoon or two.)

Store in an airtight container at room temperature for up to 3 days.