Preheat your oven to 350 degrees.

With a mixer combine the sugar and butter, then add the egg.

Mix in the mashed banana.

In a separate bowl, whisk together the flour, baking powder, baking soda, salt and cinnamon.

Add the dry mixture to the banana mixture and gently combine.

Line a 12 cup muffin tin with liners, and evenly distribute the batter between the 12 liners.

Bake for 20 minutes.