In Cincinnati chili parlors, chili is often served over spaghetti. This slimmed-down version has the consistency of a casserole, and with ziti (tubes) or gemelli (short twists), it's easily spooned up from a potluck table.
In a 12-inch skillet cook ground beef and onions until meat is brown, using a wooden spoon to break up meat as it cooks. Drain off fat. Place meat mixture to a 4- to 5-quart slow cooker. Stir in pasta sauce, kidney beans, the water, chili powder, chocolate pieces, vinegar, cinnamon, bouillon granules, cayenne pepper, and allspice.
Cover and cook on low-heat setting for 8 to 10 hours or on high-heat setting for 4 to 5 hours.
Cook pasta according to package directions; drain well. Add pasta to meat mixture in slow cooker; gently toss to combine. If desired, sprinkle with cheese.