Brown the ground beef in a large skillet over medium heat until mostly cooked through.
Add the diced onion, bell pepper, and garlic and stir to combine. Cook over medium heat until onion is translucent.
Transfer the beef mixture to a 6 quart crockpot or slow cooker.
Add the beans.
Top with diced tomatoes, tomato paste, tomato sauce, Worcestershire sauce, beef broth and hot sauce.
Next add the seasonings (chili powder, cumin, paprika, cayenne, salt, pepper and cocoa). Stir to combine.
Place the lid on the slow cooker and cook on low for 4 to 6 hours or on high for 2 to 3 hours, stirring occasionally.
Serve with toppings like shredded cheese, sour cream, tortilla chips, etc.