1. In large nonstick skillet coated with cooking spray, cook sausages over medium-low heat for 12 to 15 minutes or until no longer pink, turning often. Remove links from skillet, reserving drippings in skillet. Cool sausages slightly. Cut into thin slices. Set aside.
2. In same skillet cook onion in reserved drippings until tender.
3. In food processor bowl combine onion mixture, cream cheese, 1/2 cup of the Parmesan cheese, mayonnaise, yogurt and garlic. Cover and process until nearly smooth. Transfer to bowl. Stir in sausage, spinach, tomato and banana pepper.
4. Spoon into shallow 1-quart casserole or 9-inch pie plate coated with cooking spray. Sprinkle with remaining 1/4 cup Parmesan cheese. Bake at 400°F about 15 minutes or until hot and bubbly. Serve with KEEBLER CLUB ORIGINAL crackers.