Preheat oven to 300°F (150°C). Grease two 7×3 inch loaf pans.
In a large bowl, cream butter and sugar. Mix in eggs, mashed bananas, sour cream, vanilla and cinnamon. Mix in salt, baking soda, and flour. Mix in Nutella. Divide into prepared pans.
Bake for 1 hour, until a toothpick inserted in center comes out clean.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.