A cheddar such as Grafton or Tillamook gives this dish legendary flavor. Heat up the leftovers, covered, in the microwave, rather than in the oven, so that they don’t get too dry the second day.
Preheat oven to 350ºF. Grease a 3-quart casserole.
Cook the pasta in a large pot of boiling, salted water until al dente. Drain and set aside the pot.
For topping: In a small skillet, melt 1 tablespoon of butter, add the bread crumbs, and sauté for 1 to 2 minutes. Remove and set aside.
For sauce: In a heavy, medium saucepan, melt 3 tablespoons of butter over low heat. Stir in the flour with a whisk and cook for several minutes, stirring occasionally. In a separate saucepan, heat the milk to almost boiling, and add it to the butter and flour. Cook, stirring constantly, until the mixture thickens. Season with salt and pepper.
Put one–third of the macaroni in the bottom of the casserole. Cover it with one–third of the cheese, then pour one–third of the sauce over the cheese. Repeat, making two more layers. Spoon buttered bread crumbs over the top. Bake for 25 to 35 minutes.