Preheat oven to 400 degrees. Line or grease a muffin pan, set aside.
In a large mixing bowl, cream together the softened butter and sugar, 2-3 minutes until smooth. Add in the mashed bananas, eggs, and vanilla, mix until incorporated.
Add in the flour, salt, cinnamon, nutmeg, baking soda, baking powder, mix again until incorporated. Fold in the oats. Portion out into the prepared muffin tin. Sprinkle the muffins with extra oats as a garnish.
Bake at 400 degrees F, for 15 -20 minutes, allow to cool slightly before serving and enjoy!