Preheat oven to 350°F. Cook macaroni to al dente according to package instructions and drain.
Meanwhile, melt butter in a large heavy saucepan over medium-low heat. Stir in flour, salt, and pepper and cook 1 to 2 minutes. Whisk in milk and cook over medium heat until thickened and bubbly, stirring constantly.
Reduce heat to low and stir in cheeses until melted. Add TABASCO® Buffalo Style Sauce, chicken, green onion, macaroni and additional salt and pepper to taste; mix well.
Spoon into an ungreased 2-quart casserole dish and top with bread crumbs. Bake for 25 to 30 minutes or until heated to an internal temperature of 165°F.
Makes 8 servings.