Preheat oven to 375F and move the rack to the middle position.
Boil a pot of water and cook the egg noodles for 1 minute less than the package directions indicate. Add the broccoli to the pot 2 minutes before the noodles are done. Drain and transfer to a 9x13 casserole dish.
To the casserole dish, add the chicken, condensed soup, sour cream, garlic powder, scallions, and half the cheddar. Toss and then smooth into an even layer.
Top with the rest of the cheese, then cover with foil and bake for 25-30 minutes. Uncover and broil if desired.
Serve immediately with extra salt & pepper if needed.
