Prep: Preheat oven to 350°F and grease a 8x4" loaf tin. For easier removal, line with parchment, leaving enough overhang on each side to lift the loaf out of the tin once cooled. (Use an 8x4" for a nice tall loaf. You can use a 9x5" for a less tall loaf, but I recommend testing for doneness about 10 minutes earlier, as it will bake faster.)
Wet mixture: In a large bowl, mash ripe bananas. Add in white sugar, brown sugar, plant milk, neutral oil, and vanilla extract. Stir to combine.
Add dry ingredients: Add in the all-purpose flour, baking soda, baking powder, salt, and cinnamon (optional). Stir until about 80% combined.
Add mix-ins: Add in the chocolate chips and chopped nuts (optional). Gently fold them in to finish mixing the batter. Avoid over-mixing. It's okay if there are some small lumps as long as there are no visible streaks of dry flour.
Transfer to tin: Pour batter into prepared loaf tin and smooth out the top with your spatula.
Bake: Bake in preheated oven for 55-60 minutes. This can vary quite a bit depending on your oven. (If using a 9x5" tin, start checking earlier.) When done, a toothpick inserted into the center of the loaf should come out clean or with just a few crumbs on it — no wet batter.
Cool: Allow the loaf to cool in the tin for at least 10 minutes before carefully transferring to a wire rack. I recommend cooling for another ~10 minutes or longer, as the loaf can be a little gummy in the center if it's still piping hot.