Preheat the oven to 350°F (175°C). Spray a 9x13 inch baking dish with nonstick cooking spray to prevent sticking.

Cook the spaghetti according to the package instructions until al dente. Once done, drain the spaghetti and set it aside.

In a large skillet, heat the olive oil over medium-high heat. Add the diced onion and bell pepper to the skillet and sauté for 5 to 7 minutes until they become softened and fragrant.

Stir in the undrained can of Rotel tomatoes and let it simmer for about 2 minutes.

Add the cooked shredded chicken, salt, chili powder, cumin if using, and black pepper to the skillet. Cook for an additional 2 to 3 minutes.

Stir in the cubed Velveeta cheese, cream of chicken soup, and chicken broth. Keep stirring until the cheese melts completely.

Gently fold the cooked spaghetti into the cheese mixture, ensuring even distribution.

Transfer the spaghetti mixture to your prepared baking dish and top with shredded cheddar cheese.

Bake in the preheated oven for 20 to 25 minutes or until bubbly and the cheese is melted. Optional: broil for 1 minute for a golden top.

Let rest for 5 minutes before serving and garnish with parsley or cilantro if desired.