Step 1

Preheat the oven to 350ºF. Spray 6 giant or 12 regular muffin cups with cooking spray and set in a muffin tin.

Step 2

In a large bowl, combine the mashed bananas with the melted butter, stirring to combine. Mix in the eggs, greek yogurt, and vanilla. Set aside. In a separate bowl, combine the flour, baking soda, salt, and sugar. Fold the dry ingredients into the wet.

Step 3

Pour the batter evenly into the muffin cups. Melt Nutella in microwave for 20 seconds. Drizzle Nutella over muffins, then gently swirl the batter with a knife to form swirls of Nutella. If using giant muffin cups, bake for 20-25 minutes, or until a knife inserted in the center comes out clean. If using small muffin cups, bake for 15-20 minutes, or until a knife inserted in the center comes out clean. Allow to cool for 15 minutes before serving!