Macaroni and Cheese

1/4 cup butter or margarine, divided
1/4 cup flour
1 cup milk
2 cups grated cheddar cheese, divided
2 cups elbow macaroni, cooked, drained
1/4 cup crushed corn flakes.

Preheat oven to 350 . Melt 3 Tbsp. of the butter in a medium saucepan on low heat. Add flour; mix well. Cook 2 minutes, stirring constantly. Gradually add milk, stirring until well blended. Cook on medium heat until mixture boils and thickens, stirring constantly. Add cheese; cook until melted, stirring frequently. Add macaroni; mix lightly. Spoon into lightly greased 2 quart casserole dish; sprinkle with shredded cheese. Melt remaining 1 T of butter; toss with corn flakes. Sprinkle over casserole. Bake 20 minutes or until heated through.