1. Place bread cubes in a lightly greased 9x13 baking pan.
2. In a large bowl, beat cream cheese with an electric mixer until smooth. Add eggs one at a time, mixing well after each addition. Stir in milk, half and half, 1/2 cup of the maple syrup, and vanilla until mixture is smooth. Pour cream cream cheese mixture over the bread; cover, and refrigerate overnight.
3. Remove souffle from refrigerator, and let stand at room temperature for 30 minutes. Meanwhile, preheat oven to 350 degrees F.
4. Bake uncovered, for 50 minutes, or until a knife inserted in the center comes out clean. Pour remaining 3/4 cup maple syrup over souffle, and sprinkle with powdered sugar. Serve warm.