Preheat oven to 350 degrees. Grease med. size casserole dish - or use vegetable spray.
Cook mac and cheese according to box instructions. While pasta is boiling, brown ground beef until no longer pink. (I like to add a few dried minced onions here.) Drain off fat. Add bbq sauce to taste and set aside. (Don't drown it in sauce or it will over power your mac & cheese.)
When pasta is done add powdered cheese, butter and milk (according to package). I like to add 1/2 cup more cheddar cheese to make it creamy. Place half the pasta in bottom of casserole dish. Place bbq burger mixture in center. Use remaining pasta to mound up and around the burger.
Bake at 350 degrees until bubbly and heated through, about 20 minutes. Serve with a side of fruit and a salad.