Coat an 11-by-7-inch baking pan with cooking spray. Spread slices from 2 bananas evenly in the bottom; layer the bread on top, overlapping as necessary. Arrange the remaining bananas on top of the bread.
Whisk together the eggs, egg whites, milk, brown sugar, vanilla and cinnamon in a medium bowl. Pour the egg mixture over the bread, covering it and pushing the slices down so they are coated. Cover and refrigerate for at least 1 hour or up to 1 day.
Preheat oven to 350°F.
Sprinkle the French toast dish with pecans, if desired. Bake, uncovered, for 30 minutes, or until puffed and light golden brown. Cool 5 minutes before serving. Drizzle each serving with 1 teaspoon maple syrup.
