Preheat your oven to 180C (350F) and line a 12 muffin pan with muffin papers.

In the bowl of a stand mixer, or a large mixing bowl, add the softened butter, bananas, plain flour and brown sugar. Mix on medium, or with a spoon, for about a minute, or until combined.

Add the salt, cinnamon, vanilla extract, baking soda and baking powder, and mix until combined completely. Pour in the oats and stir until just combined.

Use a tablespoon to evenly distribute the muffin mix between your prepared muffin pan. Sprinkle a few oats on the top of each muffin as garnish.

Place the muffin tin in the oven and bake for about 15 minutes, or until the muffins are beginning to brown on the top, and a skewer inserted into the middle comes out clean.

Serve warm with a bit of butter, if desired.