I made a really good Cincinnati Chili for the snowy days here in the DC area... I was told that it tasted VERY close to Skyline Chili. Here is my recipe for 8 servings (I doubled this):
1 tablespoon vegetable oil
1/2 cup chopped onion
2 pounds ground beef
1/4 cup chili powder
1 teaspoon ground cinnamon
1 teaspoon ground cumin
1/4 teaspoon ground allspice
1/4 teaspoon ground cloves
1 bay leaf
1/2 (1 ounce) square unsweetened chocolate
2 (10.5 ounce) cans beef broth
1 (15 ounce) can tomato sauce
2 tablespoons cider vinegar
1/4 teaspoon ground cayenne pepper
1/4 cup shredded Cheddar cheese
Heat oil in a large saucepan over medium heat.
Add onion and cook, stirring frequently, until tender, about 6 minutes.
Add beef, in batches if necessary, and cook, breaking up with a wooden spoon, until browned.
Add chili powder, cinnamon, cumin, allspice, cloves, bay leaf, chocolate, beef broth, tomato sauce, cider vinegar, and red pepper. Stir to mix well.
Bring to a boil. Reduce heat to low; cover and simmer 1 1/2 hours, stirring occasionally.
It is the best if you now refrigerate overnight.
Remove the bay leaf. Reheat gently over medium heat.
Serve over hot, drained spaghetti. Top with shredded cheddar cheese.