The late Maida Heatter has about a dozen cookbooks to her name, all of them focused on baking sweets. These biscotti, our adaptation of a recipe from “Maida Heatter’s Best Dessert Book Ever,” are made with a combination of cocoa powder and bittersweet chocolate. With a flavor boost from instant espresso powder, they’re dark and rich and not too sugary. Each satisfyingly crunchy slice—perfect with coffee or dessert wine—is studded with pistachios, almonds and dried cherries. We prefer to use Dutch-processed cocoa here, as it lends the cookies a deeper, darker color than natural cocoa, but natural cocoa works, if that’s what you have on hand. Once the biscotti are fully cooled, they will keep in an airtight container for a few weeks. If they soften slightly during that time, put them into a 250°F oven for about 10 minutes; they will crisp as they cool.