Preheat oven at 340F or 170C.
For eggless versions, prepare the flax eggs in advance to let it sit for about 10 to 15 minutes until thickened.
Mash the bananas. You can either mash them until chunky or fine. If the bananas are still firm, just microwave for about 60 seconds until softened. If the bananas are under ripe, you can bake them in the oven until the skin turns black and they will be ripe enough for usage.
In a bowl, add all the wet ingredients, whisk to combine then set aside.
In another bowl, add all the dry ingredients and mix to combine.
Add the wet into the dry ingredients and use a spatula to mix until combined. The batter is thick. The batter for the eggless version is thicker which is normal. The baked muffins for the eggless version are also denser but equally delicious.
Add the chopped roasted walnuts but reserve a small amount for topping.
Scoop the batter into the prepared paper cups. In the video, I used small and firm paper cups so each muffin is about 50 g and I got 10 servings.
top with reserved chopped walnuts. Gently press down the walnuts so that they will stick to the batter during baking.
Bake for about 15 to 20 minutes or until cooked.
These muffins can be stored at room temperature for about 2 to 3 days provided if you have a cool and dry temperature. Otherwise, it's best to refrigerate earlier for up to a week or frozen for months.