In a Dutch oven, whisk water and tomato paste over medium-high heat until smooth.
Crumble in raw ground beef and break it up evenly.
Stir in onion, spices, cocoa, vinegar, Worcestershire, garlic, bay leaf, and sugar. Mix well.
Bring to a boil, then cover and simmer on low for 2 hours, stirring occasionally.
Cool, cover, and refrigerate overnight to deepen flavor and let fat solidify.
Remove solid fat and bay leaf. Reheat until hot.
Ladle over spaghetti, top with cheddar, and serve with optional toppings and a Greek salad.