The Only Mac 'n' Cheese I Love

6 tablespoons butter
1/2 lb elbow macaroni
6 tablespoons flour
3 cups whole milk
1 teaspoon salt
pepper
pinch cayenne
2 1/2 cups grated cheese(1/2 mild 1/2 sharp cheddar)
1/2 cup fine bread crumbs
1 teaspoon cajun seasoning

Cook macaroni. Melt butter in saucepan; add flour, and stirring constantly with a wooden spoon or whisk, cook over med heat 3-4 min, not letting the flour brown! Whisk in the milk in a steady stream and cook, whisking constantly, until thick and smooth, 4 min. Remove from heat. Add salt, pepper, cayenne and 2 cups cheese; stir well. Add noodle and toss. Pour into greased 2-quart baking dish. Combine remaining cheese with bread crumbs and cajun seasoning. Sprinkle over macaroni and bake at 350 until golden brown and bubbly, about 25 min.