Bring a large pot of salted water to a boil. Add the pasta and cook according to package instructions until al dente. Drain and set aside.
In a large skillet, brown the ground beef or turkey over medium heat, breaking it apart with a wooden spoon until fully cooked, about 6-8 minutes. Drain excess fat if necessary.
Stir in the taco seasoning and cook for an additional minute.
Add the beef or chicken broth, salsa, and cream cheese to the skillet. Stir until the cream cheese is melted and the mixture is smooth.
Add the cooked pasta, corn, black beans, and diced tomatoes to the skillet. Stir to combine and cook for an additional 2-3 minutes to heat through.
Remove from heat and stir in 1.5 cups of shredded cheddar cheese until melted. Reserve the remaining 0.5 cup for topping.
Serve the pasta in bowls, topped with the reserved cheddar cheese and garnished with fresh cilantro and avocado if desired.