Heat oven to 350°F. Spray bottom and sides of 13x9-inch (3-quart) glass baking dish generously with cooking spray.
In medium bowl, mix Alfredo sauce and water. Arrange half of the frozen tortellini in single layer in baking dish; top with 1/4 cup of the Country Ham, half of the spinach, half of mushrooms, half of the Alfredo sauce mixture and 1 cup of the mozzarella cheese. Repeat layers. Top with remaining 2 tablespoons country ham.
Spray one side foil with cooking spray and cover baking dish, sprayed side down. Bake 40 minutes. Remove foil; bake 10 to 15 minutes longer or until bubbly around edges and hot in center.