Preheat oven to 350°F. Grease or line a 9"x 5" loaf pan with parchment paper.
In a small bowl, mash the bananas. Whisk in the vegan butter, brown sugar, non-dairy milk, and vanilla extract.
In a large bowl, mix together the flour, baking soda, cinnamon, and salt. Fold in the banana mixture until well combined.
Transfer the batter into the prepared loaf pan. Bake for 50-55 minutes, until toothpick inserted into the center of the loaf comes out clean. Let the bread sit in the pan for about 15 minutes before transferring to a wire rack to finish cooling. Slice and enjoy!