Preheat the oven 350 degrees.
Boil elbow macaroni according to the box directions. Once finished cooking, drain the water and set noodles aside.
Place butter In a medium saucepan or skillet over medium heat. Once melted, whisk in the flour.
Stir in the milk, make sure to continually stir. Let the milk mixture come to a boil while still stirring.
Mix in the cubed Velveeta cheese. Stir until it has melted. Add in salt, pepper, and garlic powder. Stir in 1 cup of shredded cheese.
Once cheese has melted, pour the cheese mixture over elbow macaroni and stir until combined.
Pour macaroni and cheese in a 9 x 13 casserole dish that has been sprayed with non-stick cooking spray.
In a bowl, stir together pulled pork and BBQ sauce. Spoon the pork on top of the macaroni and cheese. Add remaining 1/2 cup of shredded cheese over the pork.
Cover the dish with foil and bake for 15-20 minutes or until cheese is melted and heated through.