Sauté Ground Beef: Set your Instant Pot to "Sauté" mode. Add the lean ground beef and cook, breaking it apart with a spatula, until it's browned and no longer pink. Drain any excess fat if needed.

Add Onions and Garlic: Stir in the finely chopped onions and minced garlic. Sauté for a few minutes until the onions become translucent and fragrant.

Spices and Seasonings: Add the ground cinnamon, unsweetened cocoa powder, chili powder, ground allspice, salt, and black pepper to the meat mixture. Stir well to evenly coat the meat and onions with the spices.

Tomato Sauce: Pour in the can of tomato sauce, followed by the water. Stir to combine, ensuring that the spices are well-distributed in the liquid.

Pressure Cook: Close the Instant Pot lid and set it to "Manual" or "Pressure Cook" mode on high pressure. Cook for 15 minutes. Once done, allow for a natural pressure release for about 10 minutes, then carefully perform a quick release to release any remaining pressure.

Serve: To assemble the chili, place a serving of cooked spaghetti on a plate or in a bowl. Ladle the Skyline Cincinnati Chili over the spaghetti.

Toppings: For the traditional "3-way," sprinkle finely shredded cheddar cheese generously over the chili. For a "4-way," add chopped yellow onions on top of the cheese. For a "5-way," include canned kidney beans as the final layer.

Enjoy: Serve your Instant Pot Skyline Cincinnati Chili hot and enjoy the delicious, iconic taste of this beloved Midwestern dish.