Cook macaroni according to pkg. directions, adding broccoli the last 5 minutes-drain.
In a large saucepan, melt butter, stir in the flour, garlic powder, onion powder, pepper and salt until smooth; gradually stir in evaporated milk.
Bring to a boil.
Cook and stir for two minutes or until thickened.
Remove from the heat, stir in 2 cups cheese.
Place half the macaroni and broccoli in a greased 13-in. x 9-in. baking dish or pan.
Top with half of the cheese sauce.
Sprinkle with crackers crumbs and remaining cheese.
Bake, uncovered, at 375 degrees for 20 -25 minutes or until bubbly!