Cook pasta according to package directions, omitting salt and fat. Drain pasta, and set aside.
Cook chopped green onions and garlic in hot oil in a large skillet over medium-high heat 8 to 10 minutes or until onions are tender.
Add flour, basil, and milk, whisking constantly until mixture is smooth. Add cream cheese, and cook over medium heat, whisking constantly, 8 minutes or until mixture thickens. Add Cheddar cheese, hot sauce, and salt, stirring until cheese is melted.
Spoon pasta into a 1-quart baking dish coated with cooking spray. Add cheese mixture, stirring well. Sprinkle with cracker crumbs.
Bake, covered, at 350° for 30 minutes or until lightly browned.