Preheat oven to 350°F. Generously grease a 15x10x1-inch baking sheet.
In a bowl, combine cream cheese, sour cream, sugar, cinnamon, vanilla, and bananas.
Spread filling evenly on one bread slice, then top with another slice. Spread filling evenly on second slice, then top with third slice. Repeat with remaining filling and bread.
In a bowl, combine milk, eggs, sugar, cinnamon, and vanilla. Beat until well blended.
Pour egg mixture into a shallow bowl. Dip prepared bread layers into mixture, turning to coat both sides evenly.
Place on prepared baking sheet. Bake for 8 to 10 minutes. Flip and bake for 8 to 10 minutes more, or until golden brown. Dust lightly with additional confectioners’ sugar, if desired. Serve with warm maple syrup.