This is classic Mac and Cheese, (almost) the way my mom made it. I've taken her recipe and added a cream sauce, which helps hold the casserole together and distribute the cheese a little more evenly.
1 pound of pasta
4 C shredded cheese (I prefer a mix of Fontina and Cheddar)
1 C cream or milk
2 Tbs butter
While the pasta is boiling, make a roux with half the butter and a little flour. Add the cream and a bit of cheese and season with salt and pepper to make a thick sauce. Drain the pasta and toss in the cheese sauce. Pour half into a casserole dish and cover with half the remaining cheese. Add the rest of the pasta, followed by another layer of cheese. Sprinkle top with breadcrumbs and dot with butter. Bake for 30-40 minutes at 350 degrees, or until the top is golden brown.