1.Coconut oil can be replaced with any neutral smelling oil.
2.Oil can be replaced with soft butter but as banana muffins are generally moist, butter will make it stickier. So, if using butter, consume it within 2 days.
3.Walnuts can be replaced with Pecans. Use raw nuts.
4.Any variety of sweet banana can be used.
5.Curdled milk can be replaced with unsour, fresh curd in room temperature.
6.Vanilla extract is optional. But use at least one spice, either cinnamon or cardamom powder. Using all will give nice aroma.
7.If using frozen banana, first thaw/defrost in microwave until soft. Drain the water and then mash & use the banana.