Salted Chocolate Buckwheat Cookies

1. In a food processor, puree the dates, cocoa powder, butter and vanilla until smooth, stopping to scrape down the sides with a rubber spatula as necessary. This can take up to 5 minutes. Add the flour, baking powder and espresso powder and process until a very smooth dough forms. Add the chocolate and process again until the dough is smooth (you want the chocolate to be broken up into tiny bits). Scrape the dough out onto a large piece of parchment and shape it into a rectangular mass, roughly resembling a building brick. Wrap it tightly and chill it for at least 30 minutes.
2. Once the dough is chilled, place a rack in the middle of the oven and heat the oven to 375F (190C). Line a 13 x 18-inch half-sheet pan with parchment.
3. Use a sharp knife to divide the dough in two. Squeeze with your hands to coax each half into a rough, fat log. Use your fingers and palms to roll and refine them into smooth logs with a diameter of 1 1/4 inches. Use a sharp knife to divide the logs in half. Continue to divide each piece in half until you have 8 pieces per log, a total of 16 pieces. Arrange the cookies, flat side down, on the lined baking sheet. (The cookies won’t expand much while baking, so they can be set as close as an inch from one another.) Sprinkle a few flakes of Maldon salt over the top of each cookie, then lightly dust them with milk powder using a fine-mesh sieve (or — carefully — your fingers).
4. Bake the cookies for 10 minutes. Transfer them to a cooling rack.
5. Try to wait at least 30 minutes to eat them or they will be a bit crumbly. Store in an airtight container at room temperature for up to 3 days. The unbaked dough logs can be wrapped and refrigerated for up to 4 days, or frozen for up to 3 months. Slice and bake the dough straight from the fridge or freezer; no thawing is necessary.

Note: To make this recipe vegan, replace the dairy butter with vegan butter and omit the milk powder.