Cook pasta until al dente in a large pot of boiling salted water. Drain.
Meanwhile, in a large saucepan, melt the butter over medium heat. Add the flour and stir to form a smooth paste. Cook for about 2 minutes, being careful not to brown. Gradually add the milk and the half-and-half and simmer until thickened slightly, stirring all the while. Remove from the heat. Stir in the 3 cheeses and season with black pepper, to taste. Add the cooked pasta and mix into the cheese sauce thoroughly.
Preheat oven to 400 degrees F.
For the Classic Mac and Cheese:
1 cup coarse bread crumbs
1 tablespoon butter, melted
2 tablespoons chopped fresh parsley
Pour half of the mac and cheese into an 8 by 8 by 2-inch baking dish. In a mixing bowl toss the bread crumbs together with the melted butter, parsley, and salt, to taste. Top the mac and cheese with the bread crumb mixture and bake 15 minutes or until the topping has nicely browned and pasta is bubbly and creamy.
For the Chili Mac and Cheese:
2 tablespoons chili powder
A few dashes dried red chili flakes
1 cup crushed yellow corn chips
1 tablespoon vegetable oil
1 small lime, zested
Stir the chili powder and chili flakes into half of the mac and cheese base. Pour into an 8 by 8 by 2-inch baking dish. In a mixing bowl combine the crushed corn chips together with the oil and the lime zest. Top the mac and cheese with the corn chip mixture and bake 15 minutes or until the topping has nicely browned and pasta is bubbly and creamy.