Coat shallow 12 x 7-inch baking dish with nonstick cooking spray. Toss together bread, spinach, pepperoni, tomato, cheese and Italian seasoning in large bowl. Spread evenly in prepared dish.
Whisk together eggs, half-and-half, salt and pepper in a bowl. Pour evenly over bread mixture. Cover with plastic wrap. Refrigerate at least 2 hours or overnight.
Preheat oven to 425 degrees F.
Remove dish from refrigerator. Let stand 5 minutes.
Remove plastic wrap; cover with foil. Bake for 15 minutes. Uncover; bake 15 minutes. Let cool slightly and serve.