Preheat the oven: Set your oven to 375°F (190°C). Grease a 9x13-inch baking dish or similar casserole pan.
Sauté the aromatics: Warm the oil in a large skillet over medium heat. Add onion and bell pepper, and cook 4–5 minutes until softened.
Stir in garlic and jalapeño, and cook 30–60 seconds until fragrant.
Brown the meat: Add the ground beef to the skillet. Break it up with a spatula and cook until no longer pink, about 6–8 minutes. Drain excess fat if needed.
Season generously: Sprinkle in chili powder, cumin, smoked paprika, oregano, onion powder, garlic powder, cayenne (if using), salt, and pepper.
Stir to coat the meat evenly and toast the spices for about 1 minute.
Add the tomato base: Pour in the crushed tomatoes, tomato paste, and beef broth. Stir to combine and bring to a gentle simmer.
Enrich with cream cheese: Reduce heat to low and add the cubed cream cheese. Stir until fully melted and the mixture is smooth and creamy.
Fold in some cheese: Stir in 1/2 cup of the shredded cheddar.
Taste and adjust seasoning with more salt, pepper, or cayenne as needed.
Assemble the bake: Transfer the chili mixture to the prepared baking dish. Sprinkle the remaining 1 cup cheddar and the Monterey Jack (if using) evenly over the top.
Bake until bubbly: Place in the oven and bake 12–15 minutes, until the cheese is melted, bubbly, and lightly golden at the edges.
Rest and garnish: Let the casserole rest for 5–10 minutes to set. Top with sliced green onions, cilantro, sour cream, and diced avocado, if you like.
Serve: Spoon into bowls and enjoy as is, or pair with a simple side salad or cauliflower rice for a heartier plate.