1Heat oven to 450°F. Spray 13x9-inch (3-quart) glass baking dish with cooking spray. In 4-quart Dutch oven, heat oil over medium-high heat. Cook turkey in oil 4 to 6 minutes, stirring frequently, until no longer pink. Stir in salsa and flour. Cook 2 to 3 minutes, stirring constantly, until slightly thickened.
2Stir in remaining casserole ingredients. Heat to boiling. Spread turkey mixture in baking dish.
3In medium bowl, stir all topping ingredients just until moistened (batter will be lumpy). Pour topping over turkey mixture; gently spread to sides of baking dish.
4Bake 12 to 15 minutes or until topping is golden brown.