Heat oven to 375°F. Spray 1-quart casserole with cooking spray.
Place meatballs in medium microwavable bowl. Microwave uncovered on Medium (50%) 1 to 2 minutes or just until thawed. Place biscuits on microwavable plate. Microwave uncovered on Medium (50%) 30 to 45 seconds, turning over halfway through microwave time. (Biscuits should still be cold for easier handling.)
Cut each biscuit into 4 pieces; place in bowl with meatballs. Add vegetables, pasta sauce and olives; toss to coat. Spoon and spread mixture in casserole, making sure biscuits are evenly distributed.
Bake uncovered 30 to 35 minutes or until edges are deep golden brown and biscuit pieces are no longer doughy. Sprinkle with cheese; bake 1 to 2 minutes longer or until cheese is melted. Let stand 10 minutes before serving.