Zucchini casserole

8 cups sliced zucchini(about 2 1/2 pounds)
1 cup chopped onion
1/2 cup fat-free, less-sodium chicken broth
2 cups cooked rice
1 cup (4 ounces) shredded reduced-fat sharp cheddar cheese
1 cup fat-free sour cream
1/4 cup (1 ounce) grated fresh Parmesan cheese, divided
1/4 cup Italian-seasoned breadcrumbs
1 teaspoon salt
1/4 teaspoon black pepper
2 large eggs, lightly beaten

Preheat oven to 350°.

Combine first 3 ingredients in a Dutch oven; bring to a boil. Cover, reduce heat, and simmer 20 minutes or until tender. Drain; partially mash with a potato masher.

Combine zucchini mixture, rice, cheddar cheese, sour cream, 2 tablespoons Parmesan cheese, breadcrumbs, salt, pepper, and eggs in a bowl; stir gently. Spoon mixture into a 13 x 9-inch baking dish coated with cooking spray; sprinkle with 2 tablespoons Parmesan cheese. Bake at 350° for 30 minutes or until bubbly.

Preheat broiler. Broil 1 minute or until lightly browned