makes about 36 cookies 1 1/4 cups all purpose flour 1/3 cup natural unsweetened cocoa powder 1/2 teaspoon baking soda 1 teaspoon ground cinnamon 1/2 teaspoon ground ginger 1/2 teaspoon ground nutmeg 1/8 teaspoon ground cloves 11 tablespoons (1 stick plus 3 tablespoons) unsalted butter, room temperature 1/2 cup (packed) golden brown sugar 1/3 cup molasses 1 teaspoon vanilla extract 1/4 teaspoon sea salt 5 ounces extra-bittersweet chocolate (do not exceed 85% cacao), chopped (no pieces bigger than 1/3 inch) 1/4 cup sanding sugar or sprinkles (optional) Sift flour, cocoa, baking soda, and spices into medium bowl. Using electric mixer, beat butter in large bowl until smooth but not fluffy. Add the brown sugar, molasses, vanilla, and sea salt; beat until fluffy, about 2 minutes. Add flour mixture; beat just until blended (mixture may be crumbly). Add chopped chocolate; mix just to distribute (if dough doesn't come together, knead lightly in bowl to form ball). Divide dough in half. Place each half on sheet of plastic wrap. Form each into 1 1/2-inch-diameter log. Wrap each in plastic; chill until firm, about 3 hours. DO AHEAD: Can be made 3 days ahead. Keep chilled. Preheat oven to 325°F. Line 2 baking sheets with parchment paper. Roll logs in the sugar or sprinkles and press to adhere. Using thin sharp knife, cut logs crosswise into 1/2-inch-thick rounds. Space 1 inch apart on prepared sheets. Bake 1 sheet at a time until cookies appear dry (cookies will not be firm or golden at edges), 11 to 12 minutes. Transfer to rack; cool.