Heat oven to 350℉
Melt 3 tbsp butter in medium saucepan on medium heat
Whisk in flour, cook 2 minutes, stirring constantly
Gradually stir in milk
Bring to boil; cook and stir for 3-5 minutes (or until thickened)
Add Velveeta, cook for 3 minutes or until melted; stir frequently
Stir in macaroni
Spoon into 3 qt caserole dish sprayed with cooking oil of choice
Sprinkle with cheddar
Melt remaining butter, stir in cracker crumbs, sprinkle over cesserole
Bake 20 minutes or until heated through