Place half of the bread cubes in a shallow 1-qt. baking dish coated with cooking spray. Top with cream cheese and raspberries. In a small bowl, combine the eggs, syrup, milk and remaining bread cubes; spoon over raspberries. Cover and refrigerate overnight.
Remove from the refrigerator 30 minutes before baking. Bake at 350° for 30 minutes. Uncover; bake 15-20 minutes longer or until set.
Meanwhile, for syrup, combine the sugar, cornstarch and water in a saucepan until smooth. Bring to a boil over medium heat. Reduce heat; simmer, uncovered, for 2-3 minutes or until syrup reaches desired consistency. Add berries; mash slightly. Remove from the heat; stir in butter. Pour over strata. Serve immediately.