PREHEAT oven to 350°F. Spray 9x13-inch baking dish with cooking spray; set aside. Cook macaroni as directed on package; drain.

TOP with layers of half each of the macaroni, Velveeta and Cheddar cheese; set aside. Beat egg and milk with wire whisk until well blended. Pour half of the egg mixture over ingredients in baking dish. Repeat layers of macaroni, Velveeta and Cheddar cheese; drizzle with remaining egg mixture. Sprinkle lightly with paprika.

BAKE 15 min. Stir carefully until well blended. Bake an additional 15 min. or until macaroni mixture is heated through and top is golden brown.