Whisk the flour, salt, baking soda and baking powder together in a medium bowl.
Working in the bowl of a mixer fitted with the paddle attachment, or in a large bowl with a hand mixer, beat the butter on medium speed for about 1 minute, until smooth. Add both sugars and beat for another 2 minutes or so, until well blended. Beat in the vanilla. Add the eggs one at a time, beating for 1 minute after each egg goes in. Reduce the mixer speed to low and add the dry ingredients in 4 or 5 additions, mixing only until each addition is just incorporated. (Because you're going to add more ingredients after the flour, it's good not to be too thorough.) Still on low speed, mix in the chocolate and nut flour.
Divide the dough in half, wrap each piece airtight in plastic film and refrigerate for at least 2 hours. (The dough can be refrigerated for up to 3 days. Or, if it's more convenient for you, you can scoop the dough now and freeze it in balls. You won't need to defrost the cookies, but you will need to bake them a little longer.)
When you're ready to bake: Center a rack in the oven and preheat the oven to 350 degrees F. Line two baking sheets with parchment paper or silicone baking mats.
Edouard says to scoop the dough into mounds the size of golf balls. A medium cookie scoop with a capacity of 1 1/2 tablespoons is just right here, but you can also spoon the dough out using a rounded tablespoon of dough for each cookie. Place the dough on the lined sheets, about 2 inches apart.
Bake the cookies one sheet at a time for 8 minutes and then, using a metal spatula, gently press each mound down just a little; rotate the baking sheet. Bake for another 7 minutes or so, until the cookies are pale brown. They'll still be slightly soft in the center, but that's fine-they'll firm as they cool. Pull the sheet from the oven and allow the cookies to rest for 1 minute, then, using a wide metal spatula, carefully transfer them to racks to cool to room temperature. Repeat with the remainder of the dough, always using a cool baking sheet.
Serving: The cookies are good warm or at room temperature; good with coffee, good with tea and terrific with milk (a beverage I've never seen a grown French person sip); and even good with Armagnac.
Storing: The best way to maintain the cookies' chewiness is to store them in a zipper-lock plastic bag; they'll stay fresh for about 3 days. You can keep them longer, of course; just know that they'll get a little firmer as time passes. Or pack them in an airtight container and freeze them for up to 2 months.
"Baking Chez Moi" by Dorie Greenspan (c) Houghton Mifflin Harcourt 2014. Provided courtesy of Dorie Greenspan. All rights reserved. Photo by Alan Richardson.