Position two oven racks to evenly divide the oven into thirds and preheat oven to 350ºF. Line two baking sheets with parchment paper or silicone baking mats.

1. Working with a stand mixer fitted with the paddle attachment, or in a large bowl with a hand mixer, beat the butter, sugar and salt together on medium speed until smooth, about 3 minutes. Beat in the vanilla and the almond extract, if you’re using it, then scrape down the sides and bottom of the bowl. With the machine off, add the all-purpose flour all at once and then pulse the mixer to start blending. Mix on low speed until the flour is almost incorporated, then add the almond flour and mix only until it disappears into the mixture and the dough comes together. (For storing or freezing the dough, see the notes below)
2. Using a medium cookie scoop, scoop out walnut-size nuggets of dough or use a tablespoon. Work each piece into a compact ball between your palms and then roll it on the counter into a rope about 4 inches long. Bend the rope into a crescent, pinch the ends lightly and place on the baking sheets, leaving about 2 inches between the crescents.
3. Bake for 19 to 21 minutes, rotating the sheets top to bottom and front to back after 10 minutes, or until the cookies are golden at their tips, pale everywhere else and set, but too fragile to lift without breaking. Transfer the baking sheets to racks and let the cookies rest for 5 minutes before you give them the sugar treatment.
4. Put the sugar in a small bowl and, one by one, dredge the cookies in sugar to coat the, and place them on racks to cool. (Note: I dipped the bottoms of the cookies in sugar and then used the baker's dusting wand for the tops. The wand prevents clumping and gives the cookies a snow-covered look.