Season the boneless, skinless chicken breasts with salt and pepper, then heat 1 tablespoon of olive oil in a skillet over medium-high heat. Cook the chicken for 6-7 minutes on each side until golden brown and fully cooked, reaching an internal temperature of 165°F. Once done, remove from heat and shred the chicken with two forks, setting it aside for later.

In a large pot, bring salted water to a boil and add the macaroni. Cook the pasta according to the package instructions, usually around 8-10 minutes, until it's al dente. Drain the macaroni in a colander, then return it to the pot, keeping it warm while you prepare the cheese sauce.

In a medium saucepan, melt 2 tablespoons of butter over medium heat. Once melted, sprinkle in 2 tablespoons of flour and stir continuously for about 1 minute to create a roux. Gradually whisk in 2 cups of milk and cook for 3-4 minutes until the mixture thickens. Add the garlic powder and onion powder, stirring well to incorporate.

Lower the heat to medium-low, then add 1 cup of shredded cheddar cheese and 1 cup of shredded mozzarella cheese to the saucepan. Stir continuously until the cheeses are fully melted and the sauce is smooth and creamy. Season the cheese sauce with salt and pepper to taste.

Add the shredded chicken and cooked pasta into the cheese sauce, gently folding everything together until well coated. Pour in 1/2 cup of your favorite BBQ sauce, mixing thoroughly.

Serve the warm BBQ Chicken Mac and Cheese in bowls, optionally drizzling with extra BBQ sauce and garnishing with freshly chopped herbs like parsley or green onions.