This recipe is a family favorite. It begins with a recipe by Giada De Laurentiis for Banana Muffins with Mascarpone Cream Frosting.
When I made this recipe this weekend I didn’t have any chocolate chips on hand. I thought about using M&Ms, but then I realized a glorious thing. We have Nutella in the house!! The wonderful, creamy, nutty, chocolatey goodness that is Nutella is on the pantry shelf. So instead of mixing in semi-sweet chocolate chips, I put a teaspoon of Nutella on top of each muffin batter. I used a filet knife (but a toothpick would work too) to swirl the batter and Nutella around. Basically you drag the batter into the Nutella and then drag the Nutella into the batter. Not too much, though. You want to preserve the swirl pattern.
I only have one 12-muffin pan so I put the rest in a greased, rectangular baking dish. For the loaf I put teaspoon-sized dollops of Nutella on top of the batter spaced about 1-2 inches apart. Then I swirl as described above for the muffins. I bake at 325 degrees Fahrenheit like the recipe says but the time varies. In my oven it usually longer, but I start checking it at the 25-minute mark. I removed them whenever a toothpick poked into the center of a muffin comes out clean with no gooey batter clinging to it. (Note: it is okay if a bit of chocolate or Nutella sticks to it.) Same goes for the loaf, it is removed when a toothpick poked into the center comes out clean.