Step 1

Preheat oven to 350F. Line a 12-cup muffin pan with paper liners or generously grease (incl. the rim) with butter or nonstick spray (preferred method).

Step 2

In a large bowl, whisk together the mashed bananas, granulated sugar, vegetable oil, eggs, sour cream, and vanilla extract.

Step 3

In another bowl, toss together the flour, baking soda, and salt. Add to the wet ingredients and mix until just combined.

Step 4

Divide half of the batter into the prepared muffin pan. Place the Nutella in a small microwave-safe bowl and warm it up in the microwave for 15-20 seconds. Add a teaspoon of it to each muffin.

Step 5

Repeat and swirl the Nutella using a toothpick on top of the batter.

Step 6

Bake for 23-25 minutes or until golden brown on top.