Preheat the oven to 350ºF and line a muffin pan with 6-8 cupcake liners, depending on how many muffins you are making.
Mash the banana in a mixing bowl. Add the non dairy milk, oil, brown sugar, and vanilla extract and whisk together using a fork or a whisk.
2 medium bananas, ¼ cup brown sugar, 2 tbsp vegetable oil, 3 tbsp non dairy milk, 1 tsp vanilla extract
Add the flour, baking soda, and salt to the wet mixture and gently combine using a fork or a wooden spoon. It is okay to leave few traces of dry flour.
1 cup all purpose flour, ½ tsp baking soda, pinch of salt
Add the chopped walnuts and fold the batter until the walnuts are evenly distributed in the batter and there are no traces of dry flour. Be sure not to over-mix the batter!
8-10 crushed walnuts, or 1/3 cup vegan chocolate chips
Divide the muffin batter between the muffin tins. Top each muffin with more chopped walnuts and sliced bananas if desired.
Bake the muffins for 25-30mins, or until the tops are golden in colour. Allow the muffins to cool in the pan slightly before transferring to a cooling rack to cool completely.