Add four cups of water to a large pot and bring to a boil. Add ground beef and stir until separated. Reduce heat to a simmer.
Add onions, garlic, tomato sauce, apple cider vinegar, Worcestershire sauce, salt, cinnamon, cayenne pepper, cumin, black pepper, allspice, cloves, bay leaf, and chocolate. Bring to a boil then reduce heat to a simmer and cook for 2.5 hours. Cool, uncovered, and refrigerate overnight.
The next day, skim off all or most of the fat and remove the bay leaf. Reheat the chili over medium-low heat. Top with desired chili toppings or spoon over spaghetti.