Heat the olive oil in a large, heavy pot over medium-high heat. Add the onions and cook, stirring, until translucent, about 5 minutes. Transfer to a plate. Add the ground beef to the pot, sprinkle with 1/2 teaspoon each salt and black pepper and cook, breaking up the meat with a wooden spoon, until no longer pink, about 4 minutes. Remove from the heat and return the cooked onions to the pot; stir in the garlic.
Combine the tomato sauce, diced tomatoes, vinegar, chili powder, paprika, cinnamon, cumin, allspice, cloves and cayenne in a bowl; add to the pot along with 1 cup water and stir to combine. Bring to a simmer over medium-low heat and cook until the chili is slightly thickened, about 1 hour, 30 minutes.
Serve the chili over the spaghetti; top with chopped onion, pinto beans and grated cheddar and serve with oyster crackers on the side.