Preheat oven up to 175 degrees of Celcius with a fan function. (Upper and lower heat)
Add banana to the bowl and mash with a fork.
Make chia eggs by mixing chia seeds with water and let it sit for a few minutes.
Add all other wet ingredients and mix it.
Fold in all dry ingredients and mix slighty to combine together. Don't overmix.
Line muffin tin with paper muffins liners.
Add 2 tbsp of batter into each and put in some blueberries (3-4 berry into each).
Finish with the remaining batter fo fill 2/3 of each muffin liners and top with more blueberries.
Put the muffin tin inside of the oven and bake for 25-30 minutes.
The muffins should be light golden and toothpick should come clean.