Mix eggs, 1 1/2 cups of the milk, 1 tablespoon of the cinnamon, 3 teaspoons of the vanilla and baking powder in large bowl with wire whisk until well blended. Add bread cubes; toss to coat well. Pour into 13x9-inch baking dish sprayed with no stick cooking spray. Cover. Refrigerate at least 4 hours or overnight.
Preheat oven to 350°F. Remove casserole from refrigerator. Mix melted butter, brown sugar and remaining 1 tablespoon cinnamon in small bowl until well blended. Drizzle over casserole. Let stand 10 to 15 minutes.
Bake 20 to 25 minutes or until golden brown. Let stand 5 minutes before serving.
Meanwhile, mix cream cheese, confectioners? sugar and remaining 2 teaspoons vanilla in small bowl until smooth. Slowly stir in remaining 3 tablespoons milk. Drizzle over casserole before serving.