Whisk flour, 1 Tbsp cinnamon, baking soda, and salt in a bowl. Set aside.
In a different bowl, beat the oil, butter, and 3/4 cup of white sugar until light and fluffy.
Beat in the egg and banana, followed by the dry ingredients. Then add the milk.
Pour the bread batter into the loaf pan.
Mix 1 Tbsp cinnamon and 1/4 cup of white sugar in a bowl and sprinkle it over the top of the bread batter.
Put the loaf pan in the oven and bake for 50-55 minutes. If the top browns too quickly, cover with tinfoil lightly towards the final few minutes of baking.