Wisk eggs, 1/2&1/2 until well combined. Wisk in the Nutella leaving streaks in the egg mixture. The streaks will give you pockets of gooey Nutella once baked so mix it as much or as little as you like.
Tear the French bread into small chunks approx. 1-2" in size. A large loaf should give you about 5-6 cups of bread.
Grease a 9x13" baking pan and place half the bread chunks into the bottom and lightly press down into even layer. On top of the bread layer on half the cubed cream cheese and half of the sliced banana. Top with the remaining bread chunks and press down lightly. Top with remaining cream cheese and banana slices. Pour the Nutella egg mixture over the top and lightly tap the pan on the counter so the mixture begins to settle. Cover and refrigerate overnight. (You can also freeze it at this point) The next morning pre-heat oven to 350°F. Let bread bake come up to room temperature. Bake in hot oven for 45 minutes or until egg is set and top is lightly browned.