Cook elbow macaroni according to package directions. Drain well and rinse.
While pasta is cooking, melt butter and flour in a saucepan over medium heat. Cook 1 minute. Whisk in milk a little bit at a time until smooth. Simmer until bubbly.
Add Velveeta and ⅓ cup hot sauce to the milk mixture and whisk until melted and creamy.
Stir in chicken and cooked elbows.
Spread into a 2 quart casserole dish and finish with topping (if desired). Bake 18-20 minutes or until browned and bubbly.
Notes
To Make Sauce From Scratch:Melt ⅓ cup butter and ⅓ cup flour. and 1 teaspoon onion powder over medium heat. Stir in 3 cups whole milk until smooth and let simmer until thickened and bubbly. Remove form heat and whisk in 4 cups sharp cheddar cheese and 1/3 cup buffalo sauce.
Do not overcook the pasta.
Use rotisserie chicken and leftover pasta to make this extra fast.
If you'd like to skip the topping, sprinkle with additional cheddar cheese before baking.
Diced jalapenos, chopped bacon, or bell peppers can be added.