Coat a 13 x 9" pan** with nonstick cooking spray. Place the bread cubes (OK, pieces, at my house) in the prepared pan.
(**NOTE: Because this pan is going from being refrigerated overnight into a hot oven the next morning, I always use a metal pan or a Pyrex baking dish. Make sure you take the soufflé out of the refrigerator while the oven is preheating in the morning, to give the Pyrex time to lose some of its chill.)
In a large bowl, beat the softened cream cheese with an electric mixer until smooth.
Add the eggs, beating well after each addition. Add the milk, half-and-half, maple syrup, and vanilla. Mix until smooth.
Pour the cream cheese mixture over the top of the bread cubes. Press the bread cubes down into the mixture until all are well-coated.
Top with nuts and/or raisins, if desired. Cover the soufflé with plastic wrap, and chill for at least 2 hours, or as long as overnight.
THE NEXT MORNING or after 2+ hours: Preheat the oven to 375 degrees F. Remove the soufflé from the refrigerator and let stand for 20 minutes. (See Step #2.) Uncover BEFORE baking. (This is important. Don't ask me how I know.) =^..^=
Bake for about 35-40 minutes, or until set. (Check early the first time you make this since oven temps. are so variable.) Sprinkle the soufflé with confectioners' sugar just before serving. Serve with additonal warm maple syrup & butter, if desired.