Preheat oven to 350°. Prepare pasta according to package directions.
Meanwhile, melt 1/2 cup butter in a Dutch oven over low heat; whisk in flour and ground red pepper until smooth. Cook, whisking constantly, 1 minute. Gradually whisk in milk; cook over medium heat, whisking constantly, 6 to 7 minutes or until milk mixture is thickened and bubbly. Remove from heat.
Toss together Cheddar cheese and next 3 ingredients in a medium bowl; reserve 1 1/2 cups cheese mixture. Add remaining cheese mixture and hot cooked pasta to sauce, tossing to coat. Spoon into a lightly greased 13- x 9-inch baking dish. Top with reserved 1 1/2 cups cheese mixture.
Toss together breadcrumbs and next 3 ingredients; sprinkle over cheese mixture.
Bake at 350° for 35 to 40 minutes or until bubbly and golden brown