You can double the recipe for a 9 or 10 inch loaf pan. Bake for 50 to 60 minutes. You can bake the same recipe in a 9 x 10 inch pan too but it will be a much shorter loaf.
The bread stays good wrapped well for 4 to 5 days.
The sweetness of the bread depends on the ripeness of the bananas. Use the ripest banana for best result.
If Nutella is difficult to spread, microwave or heat for few seconds .
If you 'd rather not use Nutella, consider adding 3/4 teaspoon of cinnamon in with the dry ingredients or folding in 1/2 cup of chocolate chips or toasted nuts into the batter before pouring into the pan.