Heat the oven to 350 degrees farenheit. Grease a 9x5 loaf pan with nonstick spray.
Beat your butter, white sugar, and brown sugar together in a large bowl, for about 2 minutes until creamy and light.
Beat in the eggs, one at a time until blended.
Add in the vanilla extract and mashed banana and mix until smooth.
While mixing slowly (by hand, or with a mixer), add in the flour, baking powder, baking soda, salt and cinnamon, and stir together till just combined.
Pour the batter into the prepared bread pan.
Bake for 55-65 minutes, or until a toothpick comes out clean.
Cool in the pan for 5 minutes, then remove from the pan and continue to cool on a cooling rack, or enjoy warm.
(The bread will be much messier to slice when warm)**