PREHEAT oven to 350° F.

In a large pot, COOK macaroni according to package directions; DRAIN; RETURN to pot.

ADD milk, melted butter, pepper and salt; STIR in cheeses.

TRANSFER to a greased 2-quart casserole.

BAKE, uncovered, for 15 minutes.

Carefully STIR mixture; SPRINKLE with crushed crackers; BAKE until crackers are browned and mixture is just heated through, about 5 minutes (Note: don't overheat or mixture will curdle).

REMOVE from oven; let STAND for 10 minutes before serving.