Preheat oven to 350 degrees F. Line the bottom of a loaf pan with parchment paper.
Sift together flour, baking soda, cinnamon and salt. Whisk sugar and eggs until light and fluffy; about 10 minutes. Drizzle in oil. Add mashed bananas, sour cream and vanilla.
Fold in dry ingredients. Pour into lined loaf pan and bake 60-70 minutes.