5 T butter
¼ cup flour 
1 cup milk 
½ lb. { 8 oz. } velveeta pasteurized prepared cheese, cut in 2 inch cubes
2 cups dry elbow macaroni, cooked according to package and drained, don't over cook.
½ cup shredded cheddar cheese 
½ cup crushed ritz crackers 
Preheat oven to 350°. Melt 3 T. of the butter in medium saucepan on medium ~ low heat. Add flour; mix well. Cook 2 minutes, stirring constantly. Gradually add milk, stirring with a wire whisk until well blended. Cook on medium heat until mixture boils and thickens, stirring constantly. Add pasteurized cheese; cook until cheese is melted, stirring frequently. 
Add cooked macaroni to cheese sauce; mix lightly. Spoon into a lightly greased 2 ~ quart casserole dish; sprinkle the top with shredded cheese. Melt the remaining 2 T. butter; gently toss cracker crumbs in butter until well coated. Sprinkle over casserole. Bake 20 minutes or until heated through. Serves 6