Crumble almond paste into a food processor; add sugar and pulse until evenly combined. Add egg whites and process until incorporated. Transfer mixture to a bowl. Sift together confectioners' sugar and cocoa; gradually add to almond mixture and mix well., Drop by tablespoonfuls 2 in. apart onto parchment-lined baking sheets. Bake at 350° until tops are cracked, 17-20 minutes. Cool for 1 minute before removing from pans to wire racks. Store in an airtight container.