In a large skillet over medium-high heat, warm the oil. Slice the chicken breasts in half to ensure quicker, more even cooking. Season the chicken thoroughly with salt, pepper, chipotle powder, and garlic powder. Add the chicken to the hot pan and cook for 8 to 10 minutes on each side, or until internal temperature reaches 165ºF. Remove from heat, allow to rest for 2 minutes, then shred or chop. Combine the cooked chicken with barbecue sauce and, if using, hot sauce in a large mixing bowl. Set aside.

Meanwhile, cook the pasta according to package directions. Drain and set aside. In the same pot, melt butter over medium-low heat. Whisk in the flour until smooth, then add garlic powder, chipotle powder, salt, and pepper. Gradually pour in milk and water or broth, stirring constantly until the mixture reaches a gentle simmer. Reduce heat, then fold in the shredded cheeses. Stir until melted and smooth.

Incorporate the cooked pasta and prepared BBQ chicken into the cheese sauce. Mix thoroughly. Transfer to a 9×9-inch baking dish if a baked finish is desired. Sprinkle with additional cheddar and drizzle with barbecue sauce if preferred. Bake in a preheated 400ºF oven for approximately 15 minutes. Remove, garnish with chopped cilantro if desired, and serve immediately.