Heat oven to 350°F.

Spray 13×9-inch (3-quart) glass baking dish with cooking spray.

In 8-inch nonstick skillet, heat oil over medium heat.

Cook onion, bell pepper and garlic in oil 3 to 5 minutes, stirring frequently, until slightly softened.

Add spinach; cook about 1 minute or until it begins to wilt.

In baking dish, layer half of the baguette pieces, 1 cup of the feta cheese, ¼ cup of the Parmesan cheese, the bell pepper mixture, artichokes, olives and sun-dried tomatoes.

Top with remaining baguette pieces and remaining ½ cup feta cheese.

In large bowl, beat eggs and milk with whisk; beat in pepper flakes, salt and pepper.

Pour over bread mixture, pressing down slightly.

Sprinkle with remaining ¼ cup Parmesan cheese.

Bake uncovered 40 to 45 minutes or until golden brown and center is just set.

Let stand 15 minutes before serving.