I added rye flour for groundedness; cocoa nibs to represent strength; pepper for a touch of unpredictability; and raspberries for sharpness and verve. The raspberries are freeze-dried and their flavor takes a little time to reveal itself. While you taste them soon after the cookies cool, they really come into their own a day later.
In a bowl, sift both flours, the cocoa, and baking soda and whisk to blend.
In the bowl of a stand mixer fitted with the paddle attachment, or in a large bowl with a hand mixer, beat the butter and both sugars together on medium speed until smooth, about 3 minutes. Beat in the salt, piment d’Espelette or cayenne, and vanilla.
Turn off the mixer, add the dry ingredients all at once and pulse to start the blending. When the risk of a flour storm has passed, beat on low speed until the dough forms big, moist curds—this can take a couple of minutes, so don’t be afraid to keep mixing.
Toss in the chocolate pieces, nibs, and raspberries and mix to incorporate. Sometimes the dough comes together and cleans the sides of the bowl and sometimes it crumbles—it’ll be fine no matter what.
Turn the dough out, gather it together and, if necessary, knead it a bit to bring it together. Divide the dough in half. Shape each half into a log that is 1 1/2 inches (36 mm) in diameter. (The length will be between 7 and 8 inches (18 and 20 cm), but don’t worry about it—it’s the diameter that counts here. If you get a hollow in either of the logs, just start over.)
☞ TESTER TIP: To make sure there are no hollow spots in your logs, give them a brief squeeze.
Wrap the logs in plastic wrap and freeze them for at least 2 hours, or refrigerate for at least 3 hours.
Using a chef’s knife, slice one log of dough into 1/2-inch-thick (12-mm) rounds. (Don’t worry if they crack, just pinch and squeeze the bits back into the cookie.) Arrange the rounds on the baking sheet, leaving about 2 inches (5 cm) between them. If you’d like, sprinkle the tops sparingly with flaky salt.
☞ TESTER TIP: If the cookie logs are difficult to slice, let them warm up for 10 minutes at room temperature before slicing.
Bake the cookies for 12 minutes—don’t open the oven door to check, just let them bake. They won’t look fully baked and they won’t be firm, but that’s the way they’re supposed to be.
Transfer the sheet to a rack and let the cookies cool until they’re only just warm or at room temperature. Repeat with the remaining log of dough, using a cool baking sheet.