Preheat oven to 350° and line a 8"-x-4" loaf pan with parchment paper.
In a large bowl, combine banana, sugar, milk, oil, and vanilla. Whisk until smooth.
In a medium bowl, whisk to combine flour, baking soda, cinnamon, and salt. Fold dry ingredients into wet ingredients until just combined.
Transfer batter to prepared loaf pan and bake until top is golden and a toothpick inserted into the center of the banana bread comes out clean, 40 to 42 minutes. Let cool 10 minutes, then remove from pan and let cool completely.