Pecan Shortbread Cookies

~from Savoring Time in the Kitchen

2 sticks (8 ounces) unsalted butter at room temperature (or use salted butter and add less salt below)
1/2 cup granulated sugar
1/4 cup confectioners' sugar, sifted before measuring
1/2 teaspoon salt
2 large egg yolks, at room temperature
1-1/2 cups all-purpose flour
1/2 cup toasted pecans, finely chopped

Sanding sugar, or ground pecans, if desired for decoration

Preheat oven to 350F. Place whole pecans on a small baking pan and toast in the oven for approximately 6-7 minutes. Remove and set aside to cool for 30 minutes. Place pecans in a food process along with 1 tablespoon flour and pulse until finely ground.

In a stand mixer with the paddle attachment, mix the butter on medium speed until it is smooth and creamy. Add both sugars and salt and continue to mix until smooth but not fluffy, about 1 minute. Add the pecans and mix together briefly. Reduce mixer speed to low and beat in 2 egg yolks, one at a time, mixing until well blended.

Turn off the mixer and add the flour. Cover the mixer with a towel and pulse slowly about 5 times so that the flour doesn't fly out. Remove the towel and mix for about 30 seconds more, or until the flour is just blended in and the dough looks uniformly moist. Use a spatula to work in any flour remaining on the bottom of the bowl. Work the dough as little as possible. You want a soft, moist, clumpy dough.

Scrape the dough onto a lightly floured work surface. Gather it into a ball and cut it in half.  Roll each piece into a smooth log about 9 inches long, adding just enough flour to keep it from sticking to the work surface.  Wrap the logs well with plastic wrap and chill for at least 2 hours.  Overnight will yield the best results.

When ready to bake, position a rack in the center of the oven and preheat 350F degrees. Line two baking sheets with a silicone mat or parchment paper.

Place one log of chilled dough on a work surface or piece of waxed paper and sprinkle the roll in sanding sugar (or ground pecans), pressing in all around. Trim the ends of the roll if they are uneven and slice the log into 1/3-inch-thick cookies.

Place the cookies on a baking sheet at least an inch apart and bake for about 15 to 20 minutes (depending on your oven), rotating the baking sheet halfway through. The cookies should be light brown on the bottom, lightly golden around the edges and pale on top. Let the cookies rest about five minutes before removing from the baking sheet.

Repeat with the remaining log of dough on the second baking sheet, or, if using the same baking sheet allow it to cool completely.

The dough may be kept in the refrigerator for up to 3 days or frozen for up to 2 months.

Adapted from Dorie Greenspan's Baking, from My Home to Yours.