Preheat the oven to 180 degrees Celsius, gas mark 4. Line a muffin tin with cupcake papers and set aside.
In a small bowl, combine the flaxseed with 1/3 cup water. Stir and let it stand for around 5 minutes or until thickened.
In a bowl, mash the bananas using a fork, then add in all the remaining ingredients leaving the flour till last. Once combined, spoon the mixture into the muffin cases – use an ice cream scoop if you have one, to get nice even muffins.
At this point (this is optional) you can top each muffin with some nuts, chocolate chips or some oats for more flavour.
Bake in the middle of the oven for around 20-25 minutes or until a toothpick inserted the centre of each muffin comes out clean. Let cool completely on a wire rack before serving. Enjoy!