These special butter cookies are characterized by a very delicate crumb, melt-in-your-mouth texture, and rich nut flavor. The cookies hold their fat round shapes in the oven without spreading much because the dough contains very little sugar and is mixed only enough to blend the ingredients together.
When possible, I like to let the dough for this type of cookie rest for at least hours at room temperature (or covered and refrigerated for up to 2 days before baking). It’s easiest to shape them before they rest. Remove them from the fridge at least 30 minutes before baking. However you can also bake them right away after mixing, if needed.
Pulse the nuts in the bowl of a food processor fitted with a steel blade until half of them look pulverized and the rest look chopped. Transfer the nuts to a bowl and set aside. Wipe the bowl of the food processor with a paper towel to remove excess oil from the nuts.
Put the granulated sugar in the processor and process until it is fine and powdery. Add the flour and salt and pulse just to mix. Add the butter, vanilla, and the egg yolk if using. Process until the mixture looks damp and begins to clump together. Add the nuts and pulse just until combined. Transfer the dough to a bowl. Cover and refrigerate the dough for at least 2 hours, preferably overnight.
Preheat the oven to 325°F. Position the racks in the upper and lower thirds of the oven. Shape slightly more than level tablespoons of dough into 1 1/4-inch balls. Place 2 inches apart on cookie sheets. Bake for 22 to 24 minutes, or until lightly colored on top and golden brown on the bottom. Rotate the cookie sheets from top to bottom and front to back halfway through the baking time to ensure even baking.
While baking, put the powdered sugar in a small bowl.
When the cookies are done, let them cool on the pan for 5 minutes, and then sieve powdered sugar over the top of each one. Cool completely on a rack before storing. May be stored, airtight, for at least 2 weeks. Sieve additional powdered sugar over the cookies before serving, if necessary.
My career was sparked by a single bite of a chocolate truffle, made by my Paris landlady in 1972. I returned home to open this country’s first chocolate bakery and dessert shop, Cocolat, and I am often “blamed” for introducing chocolate truffles to America. Today I am the James Beard Foundation and IACP award-winning author of ten cookbooks, teach a chocolate dessert class on Craftsy.com, and work with some of the world’s best chocolate companies. In 2018, I won the IACP Award for Best Food-Focused Column (this one!).