Brown the meat: Heat a large pot or Dutch oven over medium-high heat. Add the ground beef and cook, breaking it up with a spatula, until browned and no longer pink, about 5–7 minutes.
If there’s excess grease, spoon off most of it, leaving a little for flavor.
Sauté the aromatics: If the pot looks dry, add the oil. Stir in the onion, bell pepper, and jalapeño. Cook until softened, about 4–5 minutes.
Add the garlic and cook 30 seconds until fragrant.
Bloom the spices: Stir in chili powder, cumin, smoked paprika, cinnamon, cayenne (if using), salt, and black pepper. Cook 30–60 seconds to release the flavors.
Add the base: Mix in the tomato paste and cook 1 minute. Stir in pumpkin puree, diced tomatoes, and beef broth until smooth and combined.
Simmer: Bring to a gentle boil, then reduce heat to low.
Cover partially and simmer 20–30 minutes, stirring occasionally, until thickened and glossy. Add a splash of water or broth if it gets too thick.
Finish and balance: Stir in apple cider vinegar or lime juice. Taste and adjust salt, pepper, or heat as needed.
For extra richness, swirl in a tablespoon of butter before serving.
Serve: Ladle into bowls and top with sour cream, cheddar, avocado, cilantro, or green onions. Enjoy hot.