Pre-heat the oven to 350°. Place the almonds on a baking sheet and toast them in the oven for 10 to 15 minutes. Stir half way through the baking time to ensure they are toasted evenly. Remove from oven and cool completely.
Place the almonds in a food processor fitted with the metal blade and pulse until they are finely ground to the consistency of cornmeal. Do not over-process them or you will have nut butter.
Add the butter, and powdered sugar. Pulse the processor a few times then add the flour vanilla, almond extract, and salt. Run the food processor until the dough comes together in a clump.
Wrap the dough in plastic wrap and refrigerate for 6 hours.
Preheat the oven to 375°. Line two baking sheets with parchment paper. Place the 2 ½ cups of powdered sugar in a large bowl or pie plate and set aside. You will use this later to coat the cookies.
Roll level teaspoons of dough into small balls and place them about an inch apart on the baking sheets. Bake 12 to 15 minutes until they are a pale golden color. Let the cookies cool for 3 to 5 minutes on the baking sheets until they are cool enough to handle but still warm.
Transfer the warm cookies directly to the powdered sugar and roll them to cover completely with the sugar. Set aside to cool completely (the powdered sugar will melt into the hot cookies and look goopy). After completely cooled, roll the cookies once more in the powdered sugar.
Video
Notes
For a nice, thick coating of sugar, roll the cookies in powdered sugar twice:
First coating: Roll the hot, freshly baked cookies in powdered sugar right away. The sugar will melt slightly and look a bit goopy, don’t worry, that’s normal. Let the cookies cool completely.
Second coating: Once cooled, roll them in powdered sugar again. This final coating gives them their signature snowy-white look and a thick, even layer of sweetness.