Two-Cheese Squash Casserole

INGREDIENTS

• 4 pounds yellow squash, sliced
• 1 large sweet onion, finely chopped
• 1 cup (4 oz.) shredded Cheddar cheese
• 1/2 cup chopped fresh chives
• 1 (8-oz.) container sour cream
• 1 teaspoon garlic salt
• 1 teaspoon freshly ground pepper
• 2 large eggs, lightly beaten
• 2 1/2 cups soft, fresh breadcrumbs, divided
• 1 1/4 cups (5 oz.) freshly shredded Parmesan cheese, divided
• 2 tablespoons butter, melted