In a Dutch oven or large pot over medium-high heat, heat the olive oil until shimmering. Add the diced onions and cook until soft and translucent which should take about 5 minutes.
Add in the chopped chocolate, minced garlic, oregano, cinnamon, allspice, and cloves, letting them cook until fragrant, which should take about 30 seconds.
Pour in the beef broth, tomato sauce, vinegar, tomato paste, and Worcestershire sauce into the pot, stirring to combine well.
Stir in the ground beef, breaking it apart as you do so (I used a potato masher as you can to break it up finely). Bring the mixture to a boil.
Lower the heat and let your chili simmer until it thickens, which should take around 20 to 25 minutes.
Season the chili with salt and pepper to your liking. Taste the chili and adjust the seasoning if desired.
Place some cooked spaghetti in a bowl and top it with a generous amount of chili. Add your preferred toppings: cheese, beans, onions, and few oyster crackers.