Preheat the oven to 325 degrees F. Line a baking sheet with parchment paper. Depending on the size of your pan, you may need to use two pans or do two batches.

In a medium-sized bowl, combine the pecans and flour. Set aside.

Using a handheld or stand mixer, beat the butter and confectioner's sugar. Add the butter mixture to the bowl with the pecans and flour, then mix until all the ingredients are incorporated and you form a dough. Place the dough in the fridge for 5-10 minutes to make it easier for rolling.

Spray your palms with a little nonstick cooking spray or dampen with a little water to prevent the dough from sticking to your palms. Shape the dough into 40 tablespoon-sized balls (about 14g); if you wish to do 20 large ones instead, you can do that too. These cookies do not spread when baked, so they don't need to be spread far apart on the baking sheet, just enough so they're not touching.

Bake for 20-25 minutes or until lightly browned.

Add the confectioner's sugar to a small bowl. Toss the warm cookies in the confectioner's sugar to coat, then place on a wire rack to cool.