Heat oven to 350°F and toast cashews in a single layer until a shade darker, about 10 to 12 minutes. About halfway through the toasting time, toss the nuts around to redistribute them for even coloring. Let cool completely. You can hasten this along by transferring them to the freezer for a few minutes.

Place cooled cashews, flour and salt in the workbowl of a food processor. Clear the kitchen of toddlers and others sensitive to loud noises, then grind the mixture to a fine powder. Pour mixture into a bowl and set aside briefly.

Add butter and *only* 1/2 cup of the powdered sugar to the empty food processor and run the machine until the mixture is creamy and combined. Add the vanilla and mix.

Add the nut-flour mixture and pulse the machine until it is just combined. Scrape the soft cookie dough back into the bowl that held the nut-flour mixture, cover it with plastic wrap, and refrigerate it until firm, about an hour.

Heat your oven back to 300°F. Place remaining 1 1/2 cups powdered sugar in a wide bowl.

Using your hands, scoop tablespoon-sized (about 1-inch round) balls of the chilled cookie dough into your palms and quickly roll them into little balls. Place them evenly on a parchment-lined baking sheet an inch apart.

Bake 20 to 25 minutes, until they feel dry on the outside, but still quite soft. (Don’t fret!)

Let cool on sheets for a few minutes, then gently roll the hot cookies in the powdered sugar before transferring them to racks to cool completely.

Cookies keep in an airtight container for at least a week, probably two, though never at my place. They can be frozen for as long as you trust your freezer. They occasionally benefit from a fresh coating of powdered sugar before serving.